THE  LIBRARY 
OF 

THE  UNIVERSITY 

OF  CALIFORNIA 

LOS  ANGELES 


& 


MED1CAL  CHEMISTRY> 


INCLUDING  THE  OUTLINES  OF 


Organic ,1  Physiological  Chemistry. 


BASED  IN   PART  UPON   RICHE'S  MANUAL  DE  CHIMIE. 


C  GILBERT  WHEELER, 

Professor  of  Chemistry  in  the  University  of   Chicago,   and  formerly 

Professor  of  Organic  Chemistry  in  the  Chicago 

Medical  College. 


SECOND  AND  REVISED  EDITION. 

PHILADELPHIA: 
LINDSAY    &    B  L  A  K  I  S  T  O  N. 

CHICAGO: 
S.  J.   WHEELER. 

1879. 


OTHER  WORKS  BY  PROF.  WHEELER. 


DETERMINATIVE  MINERALOGY.     A  practical  guide  to  the  recogni- 
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Price $1.00. 

NATURAL  HISTORY  CHARTS.  Five  in  number,  one  each  of  the  fol- 
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MINERALS,  ROCKS  and  FOSSILS.  In  all,  over  700  illustrations  Wholly 
hand  colored  •  Price  of  each  chart,  $7.00.  The  set, $30.00. 

NATURAL  HISTORY  PRIMER.  A  concise  descriptive  work  on  ZOOL- 
OOY  aud  MINERALOGY.  Price $1.90. 

CATALOG  US  POLYGLOTTUS,  Or  classified  list  of  the  more  important 
animals,  minerals  and  fossils  in  Latin,  Ei  glirh,  French,  German  aud 
Spanish;  for  Scientific  Travelers,  Collectors,  Curators  of  Museums 
and  others.  Price $2.00. 

IN    PREPARATION. 
THE  CHEMISTRY  OF  BUILDING  MATERIALS. 


COPYRIGHT 
C.    GILBERT    WHEELER. 

1878. 


CONTENTS. 


INTRODUCTORY,  -  7 

CLASSIFICATION  OF  ORGANIC  COMPOUNDS,  10 

HOMOLOGOUS  SERIES,  -  12 

HYDROCARBONS,  -  18 

ALCOHOLS,  -  44 

MONATOMIC,  46 

"  DIATOMIC,  -  58 

TRIATOMIC,  64 

ETHERS,  69 

ALDEHYDS,  -  85 

ACIDS,  -  -90 

McfNATOMIC,  -                                                         96 

POLYATOMIC,  -                                             112 

ALKALOIDS  OR  BASES,  -                               -      127 

ARTIFICIAL,  -      132,  170 

NATURAL,  -      137 

NEUTRAL  FATTY  BODIES,  -                             174 

SUGARS,                   -  -      181 

GLUCOSIDES,  193 

VEGETABLE  CHEMISTRY,  -      199 

CELLULOSE,  -  205 

STARCH,  -                               -      210 

DEXTRIN,  -               -                            214 

GUMS,      -  -      216 


PACK. 

ANIMAL  CHEMISTRY,  221 

ALBUMINOIDS,  -  225 

FIBRIN,  -  -  231 

CASEIN,  -  -  -  233 

DIGESTION,  -  236 

SALIVA,  -  237 

GASTRIC  JUICE,  242 

BILE,  -  -  250 

PANCREATIC  JUICE,  261 

CHYLE,  LYMPH,  -  270 

BLOOD,  272 

H^EMOGLOBULIN,  285 

CHEMICAL  PATHOLOGY  OF  THE  BLOOD,  -  294 

RESPIRATION,  301 

ANIMAL  HEAT  —  MUSCULAR  POWER,  316 

ASSIMILATION,  321 

SECRETION — .THE  URINE,  333 

CHEMISTRY  OF  NORMAL  URINE,  339 

"  "  ABNORMAL  "  347 

URINARY  SEDIMENTS,  352 

"  CALCULI,  353 

ANALYSIS  OF  URINE,  356 

"  "  URINARY  DEPOSITS,  -  364 

"  CALCULI,  368 

SWEAT,  -  -  370 

MILK,  376 

THE  SOFT  TISSUES,  383 

OSSEOUS  TISSUE,  396 

DENTAL  "  403 

EXUDATIONS,  -  -  407 


PREFACE. 


Medical  chemistry  has  not  as  yet  secured  in  Ameri- 
can colleges  sufficiently  pronounced  attention  to  create 
a  demand  for  text-books  of  considerable  size  or  ex- 
tended scope.  In  these  simple  Outlines,  therefore,  no 
more  has  been  attempted  than  this  circumstance  would 
appear  to  warrant.  It  is  hoped  that  the  necessary 
conciseness  in  method  and  form  of  expression  has  not 
resulted  in  any  important  sacrifice  of  perspicuity  in 
thought  or  arrangement. 

It  would  have  been  easier  to  prepare  a  larger  work. 
From  the  bewildering  wealth  of  results  afforded  by  the 
labors  of  investigators  in  this  branch  of  science,  the  ap- 
propriate selection  of  that  suited  to  the  wants  of  stu- 
dents was  by  no  means  an  easy  task. 

It  is  assumed  in  these  Outlines  that  those  entering 
upon  the  study  of  Medical  Chemistry  have  previously 
made  themselves  acquainted  with  Inorganic  Chemistry 
as  taught  by  some  recent  author,  such  as  Miller  or 
Barker,  or  have  at  least  become  familiar  with  the  gen- 
eral principles  of  modern  chemical  philosophy.  The 
author  taking  this  for  granted,  has  not,  therefore,  en- 
cumbered the  work  with  a  restatement  of  that  which 
appertains  to  the  theory  of  chemistry  in  general. 

In  addition  to  the  organic  portion  of  Riche's  Man- 
uel de  Chimie,  a  translation  of  which  by  the  author 


PREFACE. 

has  served  in  part  as  basis  for  these  Outlines,  the 
works  of  Miller,  Fownes,  Williamson,  Roscoe,  and 
others  have  been  freely  used,  while  the  chemical 
journals  of  Europe  and  America,  including  their  latest 
numbers,  have  been  consulted  and  the  data  which 
they  afforded  utilized. 

Where  the  excerpta  have  been  from  journals  of  too 
recent  issue  to  be  found  in  standard  authors,  a  reference 
in  brackets  has  been  made  to  the  original  source.  Of 
the  three  series  of  numbers  thus  employed,  the  first 
has  reference  to  the  list  of  journals  given  at  the  close 
of  this  work,  the  second  usually  refers  to  the  number 
of  the  volume,  though  sometimes  to  the  year,  the 
third  indicates  the  page. 

Lest  any  regard  the  number  of  characteristic  re- 
actions of  the  more  important  compounds  as  insuffi- 
cient, it  should  be  stated,  that  it  was  not  within 
the  plan  of  the  author  to  adapt  this  work  to  the 
requirements  of  an  analytical  manual.  Xot  more 
than  two  or  three  analvtical  tests  are  therefore  given 

*J  O 

as  a  rule,  and  even  this  nuniber  only  in  the  case  of  the 
leading  compounds.  A  similar  explanation  might  be 
proffered  to  any  who  may  miss  the  full  technical  de- 
tails relative  to  certain  compounds  which  are  usually 
given  in  works  on  applied,  or  technological  chemistry. 
Throughout  the  work,  the  centigrade  thermometer 
and  the  metric  system  of  weights  and  measures  are 
employed,  unless  otherwise  specifically  stated. 

C.  GILBERT  WHEELER. 

UNIVERSITY  OF  CHICAGO,  December,  1878. 


ORGANIC  CHEMISTRY. 


INTRODUCTORY. 

Organic  chemistry  is  the  science  of  the  compounds 
of  carbon. 

Only  a  small  number  of  other  elements  are  met 
with  in  natural  organic  substances;  they  are  hydrogen, 
oxygen  and  nitrogen,  sometimes  also,  sulphur,  phos- 
phorus, and  very  rarely  certain  other  elements. 

Chemists  have  succeeded  in  incorporating  most  of 
the  elemental  substances  in  organic  bodies,  yet  the 
larger  number  even  of  the  artificial  compounds  include 
only  the  four  elements  first  named. 

Paraffine  is  found  by  analysis  to  contain  only  carbon 
and  hydrogen,  and  is  therefore  called  a  hydrogen- 
carbide.  The  hydrocarbides  are  compounds  so  stable 
and  fundamental  that  some  chemists,  as  Schorlemrner 
for  instance,  have  even  defined  organic  chemistry  as 
"  the  chemistry  of  hydrocarbons  and  their  derivatives." 

From  alcohol,  or  sugar,  we  may  obtain  carbon  and 
water.  These  bodies  therefore  are  composed  of  three 
elements:  carbon,  hydrogen  and  oxygen,  and  are  called 
carbohydrates  ;  though  by  some  chemists,  this 
terra  is  restricted  to  those  compounds  containing  car- 


8  ORGANIC     CHEMISTRY. 

bon  with  hydrogen,  and  oxygen  in  such  proportions  as 
would  form  water. 

If  albumen  is  decomposed  by  heat,  the  result  is  not 
only  carbon  and  water,  but  also  ammonia ;  this  sub- 
stance accordingly  is  nitrogenous. 

The  number  of  organic  bodies  is  very  great.  As  they 
are  composed  of  a  small  number  of  elements  only,  it 
may  be  concluded  that  the  latter  unite  in  a  very  great 
variety  of  proportions  ;  it  is  therefore  of  much  impor- 
tance to  know  the  molecular  grouping  of  these  ele- 
ments. The  mere  fact  that  the  kind  and  number  of 
elements  entering  into  a  compound  are  known,  is  not 
sufficient  proof  that  its  molecular  structure  is  really 
determined.  Synthesis  must  often  be  employed  to 
confirm  the  results  of  analysis. 

Berthelot  has  specially  occupied  himself  with  the 
synthesis  of  organic  bodies,  and  has  artificially  produced 
a  great  number  of  them.  Other  chemists  have 
experimented  in  the  same  direction  during  the  last  15 
or  20  years.  However,  Gerhardt's  opinion  advanced 
in  1854;  viz.,  "  The  vital  force  alone  operates  by  syn- 
thesis and  reconstructs  the  edifice  demolished  by 
chemical  affinity,"  has  ceased  to  be  held  as  true. 

ISOMEKISM. 

Carbon,  hydrogen,  oxygen  and  nitrogen  are  not  only 
capable  of  uniting  in  a  great  variety  of  proportions, 
but  these  elements  also  furnish  numerous  isomerio 
bodies  ;  these  comprise  substances  which,  while  com- 


ISOMERISM.  9 

posed  of  the  same  elements,  have  different  properties. 
Sometimes  the  physical  properties  alone  are  different ; 
we  then  have  physical  isomerism. 

When  the  chemical  properties  themselves  are  modi- 
fied, this  is  denominated  chemical  isomerism.  Of  the 
latter,  two  kinds  are  recognized. 

I.  Polymerising  cyanogen   and   paracyanogen  are 
examples  of  this  variety  of  isomerism ;  the  latter  is  to 
be    considered    as    cyanogen,    CN  condensed,    thus 
(CN)n ;  it  is  a  polymeride  of  cyanogen.     The  weight  of 
the  molecule  of  these  two  substances  is   therefore  dif- 
ferent. 

II.  Metamerism.     At  other  times  the  isomerism 
results  from  a  different  grouping  of  elements  in  the 
compound,  the  molecular  weight  remaining  the  same. 

We  will  illustrate  this  by  two  examples  : 

a)  Methyl  acetate, 
and  b)  Ethyl  formiate. 

Acetic  acid  =  H-0-C2H30. 

Methyl  hydrate,  or  methyl  alcohol=H-O-CH3. 

When  these  two  bodies  react  they  furnish  water  and 
methyl  acetate,  CH3-O-C2H3O=C3H6O.>. 

Formic  acid=H-O-CHO. 

Ethyl  hydrate,  or  ethyl  alcohol=H-O-C3H5. 

Now  formic  acid  contains  CH2  less  than  acetic  acid, 
and  hydrate  of  ethyl  contains  one  molecule  of  CH3 
more  than  does  hydrate  of  methyl.  As  these  substan- 
ces in  reacting  lose  one  molecule  of  water,  it  is  there- 
fore clear  that  the  compound  obtained  will  have,  like 
the  preceding  one,  the  formula  C3H6O;>.  But  these 


10  ORGANIC     CHEMISTRY. 

two  products  are  not  identical  substances,  for  the  for- 
mer treated  with  alkalies  regains  the  molecule  of  water 
which  it  had  lost,  reforming  acetic  acid  and  methyl  hy- 
drate, while  the  latter  regenerates  formic  acid  and  ethyl 
hydrate. 

These  "bodies  accordingly  differ  in  the  arrangement 
of  their  molecule;  they  are  called  metameric  bodies. 

Finally  there  exist  bodies  which  are  isomerio,  prop- 
erly so-called,  possessing  the  same  formula,  having  the 
same  general  reactions,  the  same  chemical  functions, 
and  which  differ  only  in  a  very  few,  chiefly  physical, 
properties  :  such  are  oil  of  turpentine  and  oil  of  lemon, 
each  havin  the  formula  C  H  . 


CLASSIFICATION    OF    ORGANIC    COM- 
POUNDS. 

CHEMICAL  TYPES.  —  The  idea  of  referring  organic  bod- 
ies to  some  simple  model,  or  type,  was  originally  work- 
ed out  by  Laurent  and  Gerhardt,  1846-53.  though  the 
germs  of  their  ideas  on  classification  are  to  be  found  in 
the  earlier  papers  of  the  distinguished  American 
chemist  T.  Sterry  Hunt.  (Am.  Jour.  Sci.  [2]  xxxi.) 

The  four  principal  types  are  : 

H'  ) 

I.  The  hydrogen  type,  -,       >  or  H2. 

II.  The  oxide  or  water  type,  ii,   -  O"  orH2O. 

H'  ) 

III.  The  nitride  or  ammonia  tvpe,ll  '  \  N  '  "  or  IL3  N. 

II' 


ORGANIC     TYPES.  11 


IV.     The  marsh  gas  type  g ,  V  CIV  or  H4C. 

H'J 

Of  the  leading  groups  of  organic  bodies,  we  refer  to 
the  hydrogen  type:  hydrocar  bides,  aldehyds  and  the 
compounds  of  metals  and  metalloids  with  organic 
radicals. 

To  the  water  type  are  referred  the  alcohols,  ethers, 
mercaptans  and  anhydrides. 

To  the  ammonia  type  belong  the  amides,  amines, 
and  alkalamides,  all  of  which  are  denominated  com- 
pound artwfwnias. 

Marsh-gas  is  the  type  to  which  carbon  dioxide  is 
referred,  as  well  as  some  of  the  more  complex  organo- 
metallic  bodies. 

Further  details  as  to  the  relation  of  each  of  these 
classes  of  compounds  to  their  respective  types  will  be 
given  as  each  particular  class  is  studied. 

Besides  the  simple  type,  Kekule  has  proposed  com- 
pound types  formed  by  the  combination  of  two  of  the 
four  types  already  given.  Thus  the  types  of  ammonia 
and  water  combined  serve  as  a  pattern  for  carbamie 
and  oxamic  acids: 

JJ '   \  Carbamie  acid.  Oxamic  Acid. 

H'fN'"          H 
;        H 


«J.O.£J0 


12  ORGANIC     CHEMISTRY. 

HOMOLOGOUS    SERIES. 

The  members  of  a  series  of  compounds  which  have 
the  common  difference  of  CH3  are  said  to  be  homolo- 
gous. Two  or  more  such  homologous  series  are  termed 
isologous. 

The  first  idea  of  progressive  series  in  organic 
chemistry  was  enunciated  by  James  Schiel,  of  St. 
Louis,  Mo.,  in  1842.  It  was  afterwards  adopted  by 
Gerhardt  unchanged,  save  only  in  name.  (100-5-195.) 

The  subjoined  table  will  illustrate  the  nature  of  these 
series.  Each  vertical  column  forms  a  homologous 
series  in  which  the  terms  differ  by  CH2,  and  each  hori- 
zontal line  an  isologous  series  in  which  the  successive 
terms  differ  by  H2.  The  bodies  of  these  last  series  are 
designated  as  the  monocarbon,  dicarbon  group,  etc. 

C  H4    C  H2 

C2H6    C2H4    C2H8 

C3H8    C3H&    C3H4    C3HS 

CuHjo  C4H8    C4H6    C4H4  C4Hj 

C5Hi2  C5H10  C5H8    C5H6  C5H4  C5H8 

CeH14  C6H13  C6H10  C6H3  CgHg  C6H4  C8H2. 

The  terms  of  the  same  homologous  series  resemble 
one  another  in  many  respects,  exhibiting  similar  trans- 
formations under  the  action  of  given  re-agents,  and  a 
regular  gradation  of  properties  from  the  lowest  to  the 
highest  ;  thus,  of  the  hydro-carbons,  Cn  H2n+2t  the  low- 
est terms  CII4?  C.>II6i  and  C3H8i  are  gaseous  at  ordinary 
temperatures,  the  highest  containing  20  or  more  car- 


HOMOLOGOUS     SERIES. 


13 


boD -atoms,  are  solid,  while  the  intermediate  com- 
pounds are  liquids,  becoming  more  and  more  viscid  and 
less  volatile,  as  they  contain  a  greater  number  of  car- 
bon-atoms, and  exliibiting  a  constant  rise  of  about  20° 
0.  (36°  F.)  in  their  boiling  points  for  each  addition  of 
CH2  to  the  molecule. 

The  individual  series  are  given  in  the  following  ta- 
ble, with  the  names  proposed  for  them  by  A.  W. 
Hoifmann: 


Methane 
CH4 
Ethane 
02H6 
Propane 
C3H8 
Quartane 
C4H10 
Quintane 
C5Hi2 
Sex  tan  e 
C6H14 

Methene 
CH2 
Ethene 
C2H4 
Propene 
C3H6 
Quartene 
C4H8 
Quintene 
C5H10 
Sextene 
C6H12 

Ethine 

C2Il2 

Propine 
C3H4 
Quartine 
C4H6 
Quintine 
C5H8 
Sextine 

^6-Hjo 

Propone 
C3H2 
Quartone 
C4H4 
Quintone 
C5H6 
Sextone 
C6H8 

Quartune 
C4H2 
Quintune 
C5H4 
Sextune 
Cells 

The  formulae  in  the  preceding  tables  represent  hydro- 
carbons all  of  which  are  capable  of  existing  in  the 
separate  state,  and  many  of  which  have  been  actually 
obtained.  They  are  all  derived  from  saturated  mole- 
cules, CnH2n+2i  by  abstraction  of  one  or  more  pairs  of 
hydrogen- atoms. 

But  a  saturated  hydrocarbon,  CH4i  for  example,  may 


14  ORGANIC    CHEMISTRY. 

give  up  1,  2,  3,  or  any  number  of  hydrogen-atoms  in 
exchange  for  other  elements  ;  thus  marsh  gas,  CH4i 
subjected  to  the  action  of  chlorine  under  various  cir- 
cumstances, yields  the  substitution-products, 

CH3C1,  CHsCla,          CHC13,          CC14, 

which  may  be  regarded  as  compounds  of  chlorine  with 
the  radicles, 

(OH,)',       (CH8)",       (OH)'",       C"; 

and  in  like  manner  .each  hydrocarbon  of  the  series, 
CnH2n+5!)  may  yield  a  series  of  radicles  of  the  forms, 

(CnH2n+1)',  (CnII2n)",  (CnH2n.,)  '"   (CnH2n.2)-,&c. 

each  of  which  has  an  equivalent  value,  or  combining 
power,  corresponding  with  the  number  of  hydrogen- 
atoms  abstracted  from  the  original  hydrocarbon.  Those 
of  even  equivalence  contain  even  numbers  of  hydro- 
gen-atoms, and  are  identical  in  composition  with  those 
in  the  table  above  given  ;  but  those  of  uneven  equiva- 
lence contain  odd  numbers  of  hydrogen-atoms,  and 
are  incapable  of  existing  in  the  separate  state,  except, 
perhaps,  as  double  molecules. 

These  hydrocarbon  radicles  of  uneven  equivalence 
are  designated  by  Hoffmann,  with  names  ending  in  yl, 
those  of  the  univalent  radicles  being  formed  from 
methane,  ethane,  &c.,  by  changing  the  termination 


HOMOLOGOUS     SERIES.  15 

ane  into  yl ;  those  of  the  trivalent  radicles  by  chang- 
ing the  final  e  in  the  names  of  the  bivalent  radicles, 
methene,  &c. ,  into  yl;  and  similarly  for  the  rest.  The 
names  of  the  whole  series  will  therefore  be  as  follows  : 

CH4  (CH,)'  (CH2)"  (OH)" 

Methane  Methyl  Methene  Methenyl 

C2H6  (C2H5)'  (C2H4)"  (C2H3)" 

Ethane  Ethyl  Ethene  Ethenyl 

CTT  ic\  rr  \'  //"i  TT  \'  '  ir\  TJ  \ '  •  i 

3^9  \\JsH~)  IVs^^/  \Vi*V,' 

Propane  Propyl  Propene  Propenyl 

&c.  <fec.  &c. 

From  these  hydrocarbon  radicles,  others  of  the 
same  degree  of  equivalence  may  be  derived  by  partial 
or  total  replacement  of  the  hydrogen  by  other  elements, 
or  compound  radicles.  Thus  from  propyl,  C3H7,  may 
be  derived  the  following  univalent  radicles: — 


C3H3C14  C3H50 

Chloropropyl       Tetrachloropropyl  Oxypropyl 

G8H8C1,0                C3H6(CN)'  CsH^NOa) 

Trichloroxypropyl       Cyanopropyl.  Nitropropyl 

C3H4(NH2)0            C3H6(GH3)  C3H5(C2H5)2 

Amidoxypropyl      Methylpropyl  Diethylpropyl. 

From  the  radicles  above  mentioned,  all  well-defined 
organic  compounds  may  be  supposed  to  be  formed  by 
combination  and  substitution,  each  radicle  entering 
into  combination,  just  like  an  elementary  body  of  the 
same  degree  of  equivalence. 


16  ORGANIC    CHEMISTRY. 

TABLE  TO  ILLUSTRATE  THE  ARRANGEMENT  OF  THE  MORE 


Series. 

Hydro- 
carbons. 

Sulphides. 

Chlorides  or 
Haloid    Ethers. 

Alcohols. 

General 
Formula. 

CnRzn 

CwHzw+i  (  „ 
C»H2«+i  1 

C«H2«+iCl 

CnHan+i  I  0 
H           f° 

i.    C    H2 

(C  H3)2S 

C  HS  Cl 

C  H3  HO 

2.    Cz  H4 

(CaHs)2S 

C2Hs  Cl 

C2Hs  HO 

3-    C3H6 

C3H7  01 

C3H7  HO 

4.    C4  Hs 

C4H9  Cl 

C4Ho  HO 

5-    Cs  Hio 

(CsHii)2S 

CsilnCl 

CsHnHO 

6.    C6  Hi2 

C6Hi3HO 

7-    C7  Hi4 

8.    Cg  Hi6 

C8HI7C1 

CgKi7HO 

9.     €9  HiS 

10.    CioHao 

Types 

HI 

H  I  0 

H  1 

S!-o 

Hi 

H  f  " 

H  f 

H  \ 

ORGANIC    COMPOUNDS.  17 

IMPORTANT  ORGANIC  COMPOUNDS  IN  HOMOLOGOUS  SERIBS. 


Mercaptans. 

Aldehyds. 

Acids. 

Simple  Ethers. 

Compound  Ethers. 

H    t       j8 

CnH27i-i  O  I 
H              f 

C«H2«-iO  1  o 

CwHin+i  )  Q 

ffii;ft}o 

C  H3  HS 

C    H    O,H 

HC    H    02 

(C  H3)20 

C  H3  C    H    02      i. 

C2lls  HS 

C2  H3  O,H 

HC2  H3  O2 

(C2Hs)20 

CaHs  C2  H3  O2      2. 

C3  HS  O,H 

HC3  HS  O2 

C2Hs  C3  HS  02      3. 

C4Hq  HS 

C4  H?  O,H 

HC4  H?  O2 

C2Hs  C4  H?  O2      4. 

CsHiiHS 

Cs  H9  O,H 

HCs  Hg  O2 

(CsHu)20 

CsHnCs  H9  O2      5. 

C6  HiiO,H 

HC6  HiiOa 

C2Hs  C6  HiiOa      6. 

C?  Hi3O,H 

HC?  Hi3O2 

CeHs  C?  Hi3O2      7. 

TT/-1         TT  _  H/~l/i 

HCg  His02 

C2HSC8H1S02      8. 

HC9HI702 

H  (_  o 

CioHi9H,O 

HC.oH.902 

(CioH2i)2O 

C2HsC.oH.02,. 

H  / 
H) 

H  i.o 

H  i  n 
Hf° 

H  I  n 
Hf  ° 

18  ORGANIC     CHEMISTRY. 

HYDROCARBONS. 

The  origin  or  preparation  of  these  compounds,  also 
called  hydrocarbides,  and  their  properties,  physical 
and  chemical,  all  differ  largely. 

They  are  unlike  the  hydrogen  combinations  studied 
in  inorganic  chemistry  inasmuch  as  they  possess  but 
feeble  chemical  energy  Among  the  carbides  are: 
acetylene,  marsh-gas  or  methane,  ethylene,  oil  of  tur- 
pentine and  of  lemon,  benzol,  naphthalin,  petroleum, 
caoutchouc,  gutta-percha,  etc. 

The  hydrocarbides  will  be  divided  into  six  series, 
they  are  all  built  upon  the  type  of  a  molecule  of  hy- 
drogen, or  H'  ) 

IT  r 

FIRST  SERIES. 

General  Formula,  CnHan— 2. 
ACETYLENE,  OK    DIIIYDKOGEN    DICABBIDE. 

Discovered  by  Davy  and  composition  determined  by  Bertnelot 

Formula,  CaHg. 

Specific  Gravity,  0.92.    Density,  13.     Molecular  weight,  26. 

Direct    combination   of   Carbon    and  Hydrogen. 

Up  to  comparatively  recent  times  it  has  been  con- 
sidered impossible  to  unite  carbon  and  hydrogen  di- 
rectly. Berthelot,  however,  succeeded  in  doing  this  in 
the  year  1863. 

PREPARATION. — The  apparatus   which  he  employed 


CARBIDES    OF    HTDROGEfl.  19 

in  this  remarkable  synthesis,  consisted  of  a  glass  flask, 
provided  with  two  lateral  tubulures  through  which 
passed  two  metallic  rods,  terminating  in  carbon  points, 
and  which  approached  so  as  to  form,  when  connected 
with  a  powerful  battery,  an  electric  arc.  The  corks 
through  which  these  rods  passed  were  provided  with 
another  opening. each,  to  which  a  tube  was  adapted. 
Through  one  of  these  tubes  hydrogen  was  admitted 
and  through  the  other  the  products  of  the  reaction 
passed  as  they  were  formed. 

The  gas  was  collected  in  a  solution  of  cuprous 
chloride  in  ammonia.  A  red-precipitate,  acetylide  of 
copper  was  formed,  which  was  thrown  upon  a  niter  and 
treated  with  hydrochloric  acid  in  a  flask,  whereupon 
acetylene  was  set  free. 

Many  organic  compounds  produce  acetylene  on 
subjecting  their  vapors  to  the  -action  of  electric  dis- 
charges. 

Acetylene  is  also  produced,  as  a  rule,  whenever  or- 
ganic matter  is  decomposed  by  heat. 

PKOPERTIES. — Acetylene  is  a  colorless  gas,  having  a 
disagreeable  odor.  It  is  moderately  soluble  in  water, 
and  is  difficultly  liquified.  It  is  decomposed,  at  about 
the  temperature  at  which  glass  melts,  into  carbon, 
hydrogen,  ethylene,  ethyl  hydride  and  condensed 
hydrocarbides,  among  which  Bertlielot  has  found  ben- 
zol. Thenard  has  recently  obtained  it  both  as  a  liquid 
and  a  vitreous  solid.  (9 — 78 — 219.) 

Acetylene  burns  with  a  fuliginous  flame.  It  de- 
tonates violently  and  without  residue  when  mixed  with 


20  ORGANIC     CHEMISTRY. 

2.5  volumes  of  oxygen.  Cuprous  acetylide  is  an  ex- 
plosive body.  It  is  sometimes  formed  in  brass  gas- 
pipes,  and  has  been  the  cause  of  fatal  accidents. 

Chlorine  acts  upon  acetylene  with  extreme  energy; 
there  is  often  detonation  accompanied  by  light.  On 
moderating  the  action  the  compound  C2H2C18  can 
be  obtained,  which,  as  well  as  the  body  C2H2C14, 
can  also  be  prepared  by  the  action  of  antimonic  chlo- 
ride upon  acetylene. 

As  acetylene  is  not  uncommonly  studied  in  con- 
nection with  inorganic  compounds,  a  more  detailed  ac- 
count of  this  hydrocarbide  need  not  be  given  here. 

Acetylene  is  the  prototype  of  a  homologous  series 
of  hydrocarbides,  of  which  the  general  formula  is, 


n—  2. 


The  following  members  of  this  series  are  known: 

Allylene,     -  -    C3  H4 

Crotonylene,  -  C4  H6 

Valerylene,  -     C5  H8 

Rutylene,  -  C10H18 

Benzylene,          ...    C15H28. 


ETHTLENE.  21 


SECOND  SERIES. 

General  formula,  CnHfci. 

ETHYLENE. 

Synonyms:  Elayl,  Olefiant  gas. 

Formula  C8  H4. 

Sp.  Gr.  0.97.    Molecular  weight,  28. 

This  gas,  for  no  good  reason  other  than  custom,  is 
always  studied  in  inorganic  chemistry,  usually  in  con- 
nection with  the  consideration  of  illuminating  gas,  of 
which,  with  methane,  it  forms  a  prominent  constit- 
uent. 

Ethylene  is  the  type  of  a  class  of  homologous  hydro- 
carbides,  of  which  the  general  formula  is  : 


Each  member  of  the  series  is  related  to  an  alcohol 
from  which  it  may  be  obtained  on  treatment  with 
bodies  having  a  great  affinity  for  water,  as  sulphuric 
acid  or  zinc  chloride. 


O2  —  H2O  = 


22  ORGANIC     CHEMISTRY. 

We  note  the  following  members  of  this  series  : 
Ethylene,  -  .        -    C2  H4 

Propylene,      -  C3  H6 

Butylene,   -  -    C4  H8 

Amylene,        -  C5  H10 

Hexylene,  -  -  -  C6  H18 
Heptylene,  -  -  C,  H14 

Octylene,    -  -  -    C8  H16 

Nonylene,       -        -  C9  H18 

Paramylene,  -  -    C10H20 

Cetene,  -  -        C^H^ 

Duodecylene,  -  -  -  C12H24 
Tridecylene,  (Paraffin?)*  C13H86 
Tetradecylene,  C14H28. 

*A.  G.  Pouchet(66— [3]  4—868)  has  prepared  from  paraffin,  by 
oxydation  with  nitric  acid,  paraffin  acid,  C^EUsOa,  from  which 
he  deduces  Ci&Hso  aa  the  formula  for  paraffin. 


METHANE.  23 


THIKD  SEEIES. 

General  formula,  Cn 
METHANE. 

Discovered  by  Volta  in  1778. 

Synonyms;  Methyl  hydride,  Marsh  gas,  Formene. 

Formula  CH4or  CH3,  H. 

Sp.  Gr.  0.559.    Molecular  weight,  16. 

Permanent  gas,  not  liquifiable,  neutral. 

Not  discussed  in  detail  here  for  the  same  reasons  as 
given  under  Ethylene. 

Methane  is  the  first  member  of  the  following  very 
important  homologous  series: 

C  H4         methyl  hydride,  or  methane. 


C2H6 

ethyl 

tt 

"  ethane. 

C3H8 

propyl 

(t 

"  propane. 

C4H10 

butyl 

u 

"  butane. 

C5H12 

amyl 

It 

"  amane. 

C6H14 

hexyl 

it 

"  hexane. 

C7H16 

heptyl 

a 

"  heptane. 

Cg  H18 

octyl 

u 

"  octane. 

C9H2o 

nonyl 

it 

"  nonane. 

CioHa 

decyl 

u 

"  decane. 

C11H24 

undecyl 

it 

"  undecane. 

Ci2Ha, 

bidecyl 

it 

"  bidecane. 

24. 


ORGANIC    CHEMISTRY. 


CjgHag        tridecyl      "         "  tridecane. 
C14rigo        tetradecyl  "         "  tetradecane. 
C15H32        pentad  ecyl "        "  pentadecane. 
C16Hs4        hexadecyl  "        "  hexadecane. 
JSTearly  all  the  members  of  this  series  have  been 
found  in  American  petroleum,  mixed  with  members 
of  the  preceding,  or  ethylene,  series. 

Crude  petroleum,  refined  by  fractional  distillation, 
is  still  a  mixture  of  various  hydrocarbons. 

The  commercial  names  given  to  the  products  sep- 
arated at  the  different  boiling  points,  do  not  appertain 
to  chemical  compounds,  or  bodies  having  a  definite 
composition. 

Subjoined  is  a  table  based  on  Dr.  C.  F.  Chandler's 
Report  on  Petroleum,  (100 — '72-41)  showing  the 

PRODUCTS  OF  THE  DISTILLATION  OF  CRUDE  PETROLEUM.* 


NAME. 

PERCENTAGE 
YIELDED. 

P!  3 

o   . 

CHIEF  USKS. 

Cymogeue  
Rhigolene  

.625 

0°C. 
18.3 

j  Generally   uncondensed  —  used    in 
1      ice  machines. 
j  Condensed  by  ice  and  salt—  used  as 

Gasolene  

.665 

48  8 

(      an  anaesthetic. 
Used  in  making  "air-gas." 

C  Naphtha  

1 

.706 

82  2 

(  Used  for  oil-cloths,  cleaning,  adul- 

B  Naphtha  

lio 

.724 

104  4 

•<      terating  kerosene,  etc.  For  paints 

A  Naphtha 

.742 

148  8 

Benzine  

4 

Used  to  adulterate  kerosene  oil. 

Kerosene  oil  

55 

.804 

176  6 

Ordinary  oil  for  lamps. 

Mineral  sperm.... 
Lubricating  oil  
Paraffin  

.847 
.833 
Solid. 

218.3 
301.6 

Lubricating  machinery. 
Manufacture  of  candles. 

*Re-arranged  from  Dr.  C.  F.  Chandler's  Report  on  Petroleum,  presented  to 
the  Board  of  Health,  of  the  City  of  New  York,  1870. 


METHANE.  25 

UNSAFE    KEROSENE. 

Many  accidents  occur  by  explosion  of  lamps,  when 
kerosene  oil  contains  too  much  of  the  lighter  oils,  ben- " 
zine  and  naphtha.  This  makes  the  oil  too  readily  in- 
flammable, for  the  lighter  oils  are  driven  out  by  heat- 
ing (as  when  a  lamp  or  kerosene  stove  is  burning),  and 
their  vapors  mixed  with  the  oxygen  of  the  air  form  a 
dangerous  explosive  mixture.  There  is  a  law  requir- 
ing manufacturers  to  keep  kerosene  oil  free  from  these 
lighter  oils,  unfortunately  not  always  faithfully  en- 
forced. 

The  temperature  at  which  kerosene,  on  heating  in 
an  open  vessel,  emits  vapors  which  readily  catch  fire 
on  approaching  a  burning  body,  is  called,  technically, 
the  "  flash  point/'  and  that  at  which  the  kerosene  itself 
inflames  is  called  the  ''burning  point." 

FOSSIL  KESINS,  AND  BITUMEN. 

These  substances  include  amber,  retinasphalt,  as- 
phalt, retinite,  and  many  other  allied  bodies  which  are 
chiefly  contained  in  the  tertiary  strata.  In  many  in- 
stances they  are  the  products  of  the  action  of  an  ele- 
vated temperature  upon  vegetable  bodies ;  and  when 
this  is  the  case,  they  form  irregular  deposits  which  im- 
pregnate the  strata  around.  In  many  cases  the  bitu- 
mens occur  in  regular  beds,  which  appear  to  have  been 
formed  in  a  manner  similar  to  the  deposits  of  true  coal. 

Certain  important  building  stones  have  been  found 
to  be  more  or  less  impregnated  with  bitumen. 

Such  is  the  limestone  obtained  at  the  artesian  well 


26  ORGANIC    CHEMISTRY. 

quarry  in  the  city  of  Chicago,  and  the  celebrated 
Buena  Yista,  (Ohio,)  sandstone  used  extensively  in 
Cincinnati;  also  employed  at  Chicago  in  various 
prominent  public  buildings,  as  the  post-office  and 
Chamber  of  Commerce.  The  author,  in  making  a 
chemical  examination  of  the  latter  stone  for  the 
United  States  Treasury  Department,  found  it  to  coil- 
tain  2.3  per  cent,  bituminous  matter. 

OZOKERITE. 

This  substance,  sometimes  called  "mineral  wax," 
although  probably  a  mixture  of  various  hydrocarbons, 
and  possibly  of  those  belonging  to  two  or  more  series, 
may  be  briefly  referred  to  here. 

In  Moldavia  and  Galicia  it  is  found  very  extensive- 
ly as  a  brownish-yellow  solid.  It  yields  on  distillation 
a  paraffine,  which  is  the  basis  of  an  enormous  candle 
industry  in  Europe,  also  a  wax-like  body  largely  used 
in  Russia  as  a  substitute  for  beeswax.  Very  recently 
large  deposits  of  black  "  mineral  wax  "  have  also  been 
found  in  Utah,  which  on  chemical  examination  the 
author  finds  to  be  substantially  the  same  as  the  for- 
eign, though  much  purer. 


BENZOL.  27 


FOURTH  SERIES. 

General  formula  Cn  H2n-«. 

BENZOL. 

Synonyms  ;  Benzene,  Benzine. 

Formula  CgHe. 

Sp.  Gr.  0.88.    Molecular  weight,  78. 

Sp.  Gr  of  vapor  2.70. 

Density "      "          39. 

Solid  at  4  ° .    Boils  at  80.5  ° . 

Benzol  is  obtained,  with  acetylene  and  ethylene,  in. 
the  decomposition  of  organic  substances  by  heat, 
and  its  production  is  especially  favored  when  the 
temperature  is  kept  at  a  high  point  for  some  time. 

Ethylene  and  methane  form  at  a  tolerably  low 
temperature.  Acetylene,  which  is  richer  in  carbon, 
is  produced  at  a  higher  temperature.  Benzol  and 
especially  napthalin,  being  still  more  carbonaceous, 
are  formed  at  an  extremely  high  temperature. 

Berthelot  has  prepared  benzol  synthetically  by  con- 
ducting methane  tribromide,  CHBr3,  over  red-hot 
copper : 

6(CHBr3)+9Cu=C6H6+9CuBr2. 

Benzol  may  be  considered  as  condensed  acetylene: 


28  .       ORGANIC     CHEMISTRY. 

Originally,  benzol  was  prepared  by  a  process  analo- 
gous to  that  which  furnishes  methane,  i.  e.,  by  distill- 
ing benzoic  acid  with  lime, 

C,H602+CaO  =  Ca  C  O,+C6H6. 

At  present  it  is  obtained  in  immense  quantities  from 
the  tar  which  is  formed  as  an  accessory  product  in  the 
manufacture  of  illuminating  gas. 

At  the  high  temperature  of  the  gas-retort  other  pro- 
ducts, homologous  with  benzol,  are  formed  as  well; 
viz.: 

Toluene  C,  H8      boils  at  110° 

Xylene  C8  Hto       u      "  139° 

Cumene  C9  H18        "       "165° 

Cymene  C10H14       "       "  180° 

and  other  hydrocarbides,  as  napthalin  C10H8,  anthra- 
cene, also  various  sulphur  compounds,  notably  carbon 
bisulphide;  several  oxygenated  compounds,  as  phenol 
C6H6O,  cresylol  C7H8O ;  nitrogenous  compounds, 
as  aniline  C6H,N,  and  various  members  of  its 
homologous  series. 

Benzol  is  a  colorless,  neutral  liquid,  with  a  specific 
gravity  of  0.89,  almost  insoluble  in  water  but  soluble 
in  alcohol  and  ether. 

It  dissolves  sulphur,  phosphorus,  iodine,  the  differ- 
ent resins,  and  fatty  substances;  this  latter  property 
causes  it  to  be  employed  similarly  with  commercial 
"  benzine"  for  cleansing  purposes.  Care  must  be  taken 
to  rub  v.-;th  a  piece  of  cloth  having  an  open  texture, 


BENZOL.  'J 

that  it  may  remove  the  benzol  by  absorption,  without 
which  the  spot  would  reappear  after  evaporation  of  the 
solvent. 

Benzol  burns  with  a  fuliginous  flame.  Nascent 
oxygen  gives  with  it  various  products,  and  notably 
oxalic  acid  and  carbon  dioxide. 

Chlorine  and  bromine  yield  crystalline  compounds 
with  benzol.  Benzol  is  the  simplest  member  of  a 
group  of  bodies  known  as  the  aromatic  compounds,  of 
which  we  shall  proceed  to  describe  some  of  the  more 
important. 

For  distinguishing  benzol  from  the  benzine  of  com- 
merce, which  is  made  from  petroleum,  Brandberg 
recommends  to  place  a  small  piece  of  pitch,  in  a  test 
tube,  and  pour  over  it  some  of  the  substance  to  be  ex- 
amined. Benzol  will  immediately  dissolve  the  pitch 
to  a  tar-like  mass,  while  benzine  will  scarcely  be  col- 
ored. 

NlTRO-BKNZOL  C 


This  body  is  obtained  by  treating  benzol  with  fuming 
nitric  acid. 

C6H6+HN08=  C6H5(N02)+H20. 

Nitro-benzol  is  a  yellowish  oil,  crystallizing  at  37°, 
has  a  sweet  taste  and  an  odor  which  has  led  to  its  use 
in  perfumery  under  the  name  of  essence  of  mirbane. 
Taken  internally  it  acts  as  a  poison. 

On  treatment  of  nitro-benzol  with  nascent  hydrogen, 
hydrogen  sulphide,  or  other  reducing  agent,  we  obtain 


•30  ORGANIC    CHEMISTRY. 

aniline,  which  is  a  colorless  liquid,  boiling  at  182°. 
It  does  not  act  upon  litmus,  yet  combines  with  the 
acids,  forming  crystallizable  compounds. 

Aniline  gives  with  chlorine,  bromine  and  nitric  acid 
products  of  substitution  which  are  very  numerous  and 
well  defined.  It  reacts  upon  the  iodides  of  methyl, 
ethyl,  etc.,  forming  the  corresponding  amines,  or  bodies 
constructed  on  the  type  of  ammonia,  having  one  or 
'more  of  the  hydrogen  atoms  replaced  by  an  organic 
compound  radicle: 

(C6H5 

Aniline  C6H7N  =  N"  \  H 

(H 

(  C6H5 
Methylaniline  C7H9N  =  JST  \  C  H3 

(H 

Ethylmethylaniline          C9H13N  =  IS"    C  H3 

C2H5' 

C6HS  or,  when  free,  (C6H5)2,  is  the  radicle  phenyl, 
hence  aniline  is  properly  phenylamine. 

Aniline  has,  during  the  last  score  of  years,  acquired 
great  importance,  as,  under  the  influence  of  oxydizing 
bodies,  it  forms  most  remarkable  tinctorial  com- 
pounds. 

If  a  small  quantity  of  aniline  is  added  to  a  solution 
of  chloride  of  lime,  the  liquid  is  colored  violet,  which 
color  disappears  in  a  few  moments.  In  1858,  Perkins 
obtained,  by  the  action  of  potassium  bichromate  and 
sulphuric  acid,  a  beautiful  purple,  which  is  known  in 


BENZOL.  31 

commerce  as  mauve.  Shortly  after,  Verguin  obtained 
a  magnificent  red  coloring  matter  on  heating  aniline 
with  tin  dichloride. 

This  substance,  known  under  the  names  of  aniline- 
red,  jfucksin,  magenta ,  etc.,  is  now  very  economi- 
cally obtained  with  arsenic  oxide  in  place  of  the  tin 
dichloride,  which  is  reduced  to  arsenous  oxide  by  the 
reaction. 

Hoffmann  has  shown  that  aniline-red  is  a  salt  of  a 
colorless  base,  which  he  calls  rosaniline;  this  substance 
has  the  formula  C^H^N^O,  or  C.^HiglS^ILO. 

In  the  past  few  years  there  have  been  produced 
green,  yellow  and  black  colors,  all  originating  from 
aniline.  These  substances  dissolve  in  alcohol,  and  dye 
wool  and  silk  without  in  any  way  weakening  the  fabric. 
They  have  a  magnificent  lustre,  but  their  permanency 
is  not  of  the  highest  grade. 

The  consumption  of  aniline  for  dyeing  has  now  come 
to  something  enormous,  amounting  in  Germany  alone 
to  over  15,000  tons  per  annum. 

The  aniline  colors  are  employed  in  injecting  tissues 
for  microscopic  preparations. 

For  a  fuller  account  of  the  aniline  colors,  a  larger 
work  should  be  consulted. 

The  history  of  aniline  affords  one  of  the  most  re- 
markable instances  of  the  value  of  scientific  chemical 
research,  when  perseveringly  and  skillfully  applied, 
for  at  first  few  substances  seemed  to  promise  less; 
and  the  gigantic  manufacturing  industry  at  present 
connected  with  this  compound,  in  its  applications  as  a 


32  ORGANIC     CHEMISTRY. 

tinctorial  agent,  offers  a  singular  contrast  to  the  early 
experiments  upon  this  body,  when  a  few  ounces  fur- 
nished a  supply  which  exceeded  the  most  sanguine  ex- 
pectations of  the  early  discoverers  of  this  body. 

PHENOL,  C6H6O. 
Synonyms:  Hydrate-of  phenyl,  carbolic  acid  or  phenic  acid. 

It  occurs  in  castoreum,  though  usually  procured  from 
the  portions  of  coal-tar  distilling  over  between  170° 
and  195°.  They  are  agitated  with  caustic  soda, 
water  added  to  separate  the  insoluble  oils,  and  the 
phenol  dissolved  in  the  alkali  is  liberated  as  a  crys- 
talline mass,  on  decomposing  the  potassium  compound 
with  hydrochloric  acid. 

Salicylic  acid,  distilled  with  an  excess  of  lime,  also 
furnishes  phenol; 

C7H603  +  CaO  =  CaCO3  +  CeHeO. 

C  H  ) 

If  phenyl-sulplmric  acid,  (  5  >  SO4,  obtained  by  di- 
rect action  of  sulphuric  acid  upon  phenol,  is  heated 
with  potassium  hydrate  to  about  300°,  potassic  phenol 
CeII5KO  is  obtained.  Phenol  is  therefore  obtained 
from  benzol  under  the  same  conditions  as  alcohol  is 
obtained  from  ethylene,  the  corresponding  hydro- 
carbide. 

Phenol  crystallizes  in  handsome  needles,  fusible  at 
34°  and  boiling  at  188°.  It  is  little  soluble  in  water, 


PHENOL.  33 

very  soluble  in  alcohol  and  ether.  Phenol  furnishes 
with  chlorine,  bromine  and  iodine  numerous  substitu- 
tion products. 

Phenol  has  come,  like  alcohol,  to  have  a  generic 
signification,  there  being  a  number  of  analogous  com- 
pounds, though  only  this,  the  ordinary  phenol,  is  an 
important  body.  Heated  with  concentrated  nitric 
acid,  it  furnishes  yellow,  very  bitter,  crystals  of  the 
body  known  as 

PICRIC  or  CARBAZOTIC  ACID. 

Picric  acid  is  also  formed  when  silk,  benzoin,  aloes, 
indigo,  etc.,  are  treated  with  nitric  acid. 

This  acid  is  very  largely  used  in  dyeing,  either  di- 
rectly to  produce  a  yellow  color,  or,  combined  with  in- 
digo, to  produce  a  green. 

Phenol,  though  called  carbolic  acid,  does  not  decom- 
pose the  carbonates,  or  combine  with  the  metals  to 
form  true  salts.  Phenol  dissolves  in  sulphuric  acid 
without  coloration,  if  pure,  and  forms  phenyl-  sulphuric 
acid  or  sulpho-carbolic  acid 


H  f4' 

which  gives  definite  salts  with  the  metals.  One  of 
these,  the  phenyl-  sulphate  or  sulpho-carbolate  of  so- 
dium NaC6H6SO4,  is  claimed  to  have  valuable  proper- 
ties as  a  prophylactic  against  scarlet  fever. 

Phenol  gives  certain  reactions  of  the  alcohols  ;    this 


34  ORGANIC    CHEMISTRY. 

somewhat  explains  the  origin  of  the  name  given  it  by 
Berthelot.  This  body  is  the  type  of  a  class  of  com- 
pounds which  contains: 

Cresylol  obtained  from  creosote  C7  H8  O 

Phlorylol       ;'  "  "  08H10O 

Thymol         "          "       essence  of  thyme  C10HUO. 

PHYSIOLOGICAL  ACTION  OF  PHENOL. 

Phenol  attacks  the  skin,  producing  a  white  "stain. 
It  coagulates  albumen  and  is  employed  with  great 
success  as  an  antiseptic  and  disinfectant.  It  is  used 
externally  in  a  diluted  state  to  dress  wounds  which 
suppurate,  also  in  many  surgical  cases. 

It  is  sometimes  used  internally.  Large  doses  of  it 
are  poisonous.  Carbonate  and  especially  saccharate  of 
calcium  are  considered  as  antidotes  for  phenol.  Grace 
Calvert  has  announced  that  olive  or  almond  oil  is  a 
still  better  antidote. 


OIL    OF    TURPENTINE.  35 


FIFTH  SEEIES. 

General  Formula,  Cn  Han^t. 
ESSENCE,     OK    OIL    OF    TURPENTINE. 


Formula 

Density  of  vapor  compared  with  air  4.7. 

Molecular  weight,  136. 

Boils  at  160° 

Turpentine  is  extracted  from  several  varieties  of  the 
family  of  Conifer^  notably  from  the  pine,  fir  and 
larch. 

The  products  vary  somewhat  with  the  nature  of  the 
tree,  but  they  have  many  common  characteristics; 
their  composition  is  the  same,  their  density  is  nearly 
identical  and  their  boiling  point  very  nearly  so.  Their 
rotary  action  on  the  solar  ray  varies  largely. 

Isomeric  carbides  are  found  in  other  families  of 
plants,  in  the  aurantiacece  family  for  instance,  as  the 
lemons  and  oranges.  These  contain  carbides  very  dif- 
ferent, as  evidenced  by  their  odors  and  other  physical 
properties,  also  different  in  certain  chemical  relations, 
yet  having  the  same  composition  as  oil  of  turpentine. 
There  are  also  various  polymers  of  this  carbide. 

This  entire  series  of  hydrocarbons  can  be  divided 
into  three  groups.  The  first  contains  carbides  having 


36  ORGANIC     CHEMISTRY. 

the  formula  C10H16,  their  boiling  points  being  below 
200°,  and  including  : 

Density.         Boiling  at 

Oil  of  turpentine,  0.86  157°  to  160°. 

"      cloves,  0.92  140°    "  145°. 

"      lemon,  0.85  170°    "  175°. 

"      orange,  0.83  175°    "  180°. 

"     juniper,  0.84  about  160'. 

"      bergamot,  0.85  "      183". 

"      pepper,  0.86  "      167°. 

"      elemi,  0.85  «      180°. 

The  carbides  of  the  second  group  have  the  formula 
CajHsj,  their  boiling  point  is  above  200°,  they  are: 

Oil  of  copaiva,          0.91  245°. 

"      cubebs,  0.93  240°. 

The  third  group  contains  the  non-volatile  carbides, 

such  as 

Density 

Caoutchouc,     -  0.92. 

Gutta-percha,  -     0.98. 

The  rotary  power,  constant  for  each,  varies  with  the 
different  species. 

French  oil  of  turpentine  causes  the  plane  of  polar- 
ization to  deviate  to  the  left;  the  American  variety 
turns  it  13°  to  the  right;  oil  of  lemon  causes  a  devia- 
tion of  50°  to  the  right;  in  the  case  of  essence  of 
elemi  the  deviation  amounts  to  100°.  Some  of  the 


OIL    OF    TURPENTINE.  37 

essential  oils  of  the  first  group  contain  oxygen  corn- 
pounds  as  well  as  the  carbohydrides. 

The  principal  chemical  differences  between  the 
members  of  the  group  are  the  facility  with  which  they 
are  oxydized  and  their  reaction  with  hydrochloric 
acid.  Essence  of  turpentine  becomes  resinous  rapidly 
when  exposed  to  the  air  and  finally  solidifies.  Es- 
sence of  lemon  becomes  viscid  after  a  considerable 
time.  Hydrochloric  acid  produces,  with  essence  of 
turpentine,  a  liquid  and  a  solid  compound,  having  each 
the  same  composition,  C10H16,  HC1,  which,  after  a 
few  weeks,  becomes  a  dichlorhydride,  (by  some  denomi- 
nated a  dichlorhydrate),  C10H16,2HC1.  Essence  of 
lemon  also  gives  two  dichlorhydrides  at  once,  one 
liquid,  the  other  solid. 

Oil  of  turpentine  may  be  obtained  in  a  pure  state, 
on  distilling  the  commercial  article  in  a  vacuum. 
Thus  obtained,  turpentine  is  colorless,  limpid,  very 
volatile,  and  has  a  characteristic  odor.  It  is  insoluble 
in  water;  very  soluble  in  alcohol  and  ether.  It  burns 
with  a  smoky  flame;  on  exposure  to  the  air  it  oxydizes 
and  becomes  resinous.  The  same  effect  is  produced 
more  rapidly  with  oxide  of  lead  and  some  other  ox- 
ides which  render  the  oil  siccative  and  suitable  for  use 
in  painting.  J.  M.  Merrick  (100-4-289)  has  noticed 
the  circumstance,  important  in  its  technical  applica- 
tions, that  oil  of  turpentine  attacks  metallic  lead  quite 
strongly;  tin,  on  the  other  hand,  not  at  all.  Turpen- 
tine, if  exposed  to  the  air,  mixed  with  a  solution  of 
indigo,  absorbs  oxygen  and  transfers  it  to  the  indigo, 


38  ORGANIC     CHEMISTRY. 

which  loses  its  color,  yielding  a  product  of  oxydation 
called  isatin.  Under  these  circumstances,  the  turpen- 
tine does  not  change,  and  a  given  quantity  of  the  es- 
sence can  absorb  several  hundred  times  its  volume  of 
oxygen,  and  oxydize  an  indefinite  quantity  of  indigo. 
This  oxygen  is  probably  the  active  modification,  or 
ozone.  Heated  to  300°  in  a  hermetically  sealed  tube, 
it  changes  into  two  products,  one,  isomeric,  called  iso- 
turpentine,  which  boils  at  1YT°,  and  which  exerts  a 
rotatory  power  of  10°  to  15°  to  the  left;  the  other,  a 
polymer  called  metos-terebenthene,  C^H^  boiling  at 
360°. 

OTHER  SERIES  OF  HYDROCARBIDES. 

Cinnamene  C81I8  is  a  very  refractive  liquid  with 
a  density  of  0.924,  boiling  at  146°.  Styrol  which 
is  produced  from  storax  is  converted  at  205°,  into  a 
polymeric  solid,  termed  Meta-styrol  or  Draconyl.  If 
styrol  is  made  to  act  upon  acetylene,  or  ethylene,  at 
a  red  heat,  there  is  obtained  the  very  important  hydro- 
carbide  naphthalin  Ci0H8.  This  is  a  body  crystalliz- 
able  in  very  handsome  plates,  and  is  ordinarily 
obtained  from  coal  tar  by  distillation  between  200° 
and  300°;  heavy  oils  pass  over,  out  of  which  naphtha- 
lin crystallizes;  on  cooling,  the  mass  is  pressed  and 
purified  by  sublimation.  It  fuses  at  79°  and  distils  at 
220°. 

Naphthalin  is  associated  in  coal  tar  with  a  hydro- 
carbide,  beautifully  crystallizing  in  long  needles,  fus- 
ing at  93°  and  boiling  at  285°.  This  is  acenaphtene 


ALIZARIN.  39 

Ci2H10.  Another  hydrocarbide  is  also  found  in  this  tar, 
anthracene.  Its  formula  is  C14H10.  It  forms  very 
diminutive  crystalline  plates  fusing  at  210°  and  boil- 
ing at  360°.  Its  vapor  is  extremely  acrid. 

This  body  has  recently  enabled  chemists  to  repro- 
duce the  coloring  principle  of  madder;  alizarin 
CI4H8O4.  It  is  obtained  on  oxydizing  anthracene  by 
means  of  a  mixture  of  bichromate  of  potassium  and 
sulphuric  acid,  which  gives  oxyanthracene  C14H8O2. 
This,  with  fused  potassa,  furnishes  a  combination  of 
potassium  and  alizarin,  from  which  the  latter  is  pre- 
cipitated by  an  acid.  It  has  the  form  of  brilliant 
bronze-colored  needles,  identical  with  natural  alizarin 
obtained  from  madder. 

Alizarin  sublimes  at  215°  and  is  very  stable,  little 
soluble  in  cold  water,  but  readily  soluble  in  boiling 
water.  It  is  easily  dissolved  in  alcohol,  ether  and  car- 
bon bisulphide. 

Its  chemical  character,  not  quite  well  defined  as 
yet,  appears  to  place  it  among  the  phenols.  (See 
page  33.) 

The  artificial  production  of  alizarin  from  anthra- 
cene, thus  furnishing  a  cheap  substitute  for  madder, 
the  chief  dye-stuff  used  in  printing  calicoes,  is  one  of 
the  latest  and  most  noteworthy  triumphs  of  organic 
chemistry.  Thousands  of  acres  of  land  in  Europe, 
especially  in  Alsatia,  now  devoted  to  the  culture  of 
madder,  may  be  restored  to  cereal  or  other  food  agri- 
culture. 


Before  leaving  the  hydrocarbons  proper,  it  should 


40  ORGANIC     CHEMISTRY. 

be  stated  that  compounds  of  carbon  and  hydrogen  of 
extra-terrestrial  origin  have  been  found  in  certain  met- 
eorites, by  J.  Lawrence  Smith.  (80-7"6-388.) 

CAMPHOR. 

Camphor  is  usually  considered  at  this  point,  on  20- 
count  of  its  intimate  relation  to  the  oxydized  essential 
oils  in  composition,  and  to  turpentine  in  many  chemical 
reactions. 

Berthelot  regards  camphor  as  an  aldehyd.  Kekule 
places  it  among  the  ketones. 

Camphor  exists  in  various  parts  of  the  Laurijus 
camplwTCb.  To  obtain  it,  the  wood  is  finely  divided 
and  heated  with  water  in  a  metallic  vessel,  closed  by  a 
cover  filled  with  straw.  The  camphor  is  condensed  in 
grayish  crystals  on  the  straw,  forming  the  crude  cam- 
phor of  commerce  ;  it  is  afterwards  sublimed  in  a  glass 
retort  as  a  further  purification. 

Camphor  is  a  crystallized  body,  having  a  burning 
taste  and  an  aromatic  odor.  Its  density  is  0.99  at 
10°.  It  is  elastic  and  with  difficulty  .pulverized,  Avhich 
can,  however,  be  easily  effected  on  moistening  with  a 
few  drops  of  alcohol.  Water  dissolves  only  about  -^rov 
part  of  it ;  thrown  upon  pure  water  it  floats  on  the 
surface  with  a  gyratory  motion.  It  is  soluble  in  alco- 
hol, ether,  acetic  acid  and  essential  oils  ;  it  is  sublimed 
at  ordinary  temperatures  where  kept  in  close  vessels, 
and  deposits  again  on  the  cooler  side  of  the  recep- 
tacle. 

It  burns  with  a  smoky  flame  and  oxj-dizes  on  being 


RESINS,  BALSAMS,  GTJM-RESINS.  41 

boiled  with  nitric  acid,  yielding  camphoric  acid 
C10H16O4  which  is  bibasic.  Heated  with  zinc  chloride  or 
anhydrous  phosphoric  acid,  it  furnishes  Cymol  C10H14. 

The  author  found  (1-146-73)  that  on  treatment  of 
camphor  with  hypochlorous  acid  he  obtained  the  new 
body,  CjoHtfCIO,  which  he  denominates  monochlor- 
camphor',  this,  on  treatment  with  alcoholic  potassium 
hydrate,  yielded  oxycamphor  Ci0H16O2 . 

Camphor  is  very  extensively  employed  in  medicine 
and  pharmacy.  . 

EESINS,    BALSAMS,    GUM-RESINS. 

These  bodies  are  products  of  the  oxidation  of  essen- 
tial or  volatile  oils.  The  name  of  gum-resin  is  applied 
to  those  which  contain  a  gum,  and  balsam  to  those 
which  contain  essential  oils  and  an  acid,  usually  cin- 
namic  or  benzoic,  in  addition  to  the  resin  which  is 
presented  in  both.  A.  B.  Prescott,  the  eminent  au- 
thority on  proximate  analysis,  defines  balsams  as  "  natu- 
ral mixtures  of  volatile  oils  with  their  oxidation  pro- 
ducts,— resins  and  solid  volatile  acids. " 

They  are  substances  more  or  less  colored,  hard  and 
brittle.  They  are  fusible,  non-volatile,  and  burn  with 
a  fuliginous  flame.  They  are  insoluble  in  water,  gen- 
erally soluble  in  alcohol,  ether  and  essential  oils. 

Several  of  them  are  acid.  This  is  the  case  with  the 
most  important  of  them,  as  the  resin  of  the  pine,  called 
colophony,  from  which  three  isomeric  acids  have  been 
obtained — thepinic,  sylvic,  and  pimaric,  C^IiaoCX. 


42  ORGANIC    CHEMISTRY. 

This  resin  constitutes  the  fixed  residue  obtained  on 
distilling  crude  turpentine.  It  is  used  for  preparing 
varnish,  in  soldering,  and  in  certain  combinations  with 
the  alkalies,  called  resin-soaps. 

Subjoined  are  given  the  names  and  the  origin  of  the 
principal  resins,  oleo-resins,  gum-resins  and  balsams. 
With  some,  the  position  assigned  them  in  this  classi- 
fication is  not  definitely  settled. 

RESINS. 

Amber  is  found  in  the  lignites  and  in  the  alluvial 
sands  of  the  Baltic. 

Arnicin,  the  active  principle  of  Arnica  Root. 

Cannabin,  the  active  principle  of  Indian  Hemp. 

Castorin,  a  secretion  of  the  Beaver  (Castor). 

Ergotin(?),  the  active  principle  of  Ergot  of  common 
rye. 

Mastic,  a  resinous  exudation  of  the  Mastic,  or  Lent- 
isk  tree. 

Burgundy  Pitch,  an  exudation  of  the  Spruce  Fir,. 
Abies  excelsa. 

Pyrethrin,  the  active  principle  of  the  Pellitory  root. 

Rottlerin,  a  crystalline  resin  from  Kamala,  the  min- 
ute glands  which  cover  the  capsules  of  Rottlera  tinc- 
toria. 

OLEO  -RESINS. 

Copaiva,  a  resinous  juice  of  the  copaifera  officinalis 
found  in  Spanish  America. 

Wood-oil,  an  oleo-resin  from  the  Dipterocarpus 
turbinatus. 


* 

RESINS,  BALSAMS,  GUM-RESINS.  43 

Elemi,  an  exudation  of  an  unknown  tree,  (probably 
Cannarium  commune). 

Common  Frankincense,  a  concrete  turpentine  of  the 
Pinus  tceda. 

Canada  balsam,  the  turpentine  of  the  Balm  of  Gilead 
Fir,  (Abies  balsamea). 

Storax,  from  the  Liquidambar  orientate. 

GUM-RESINS. 

Ammoniacum,  an  exudation  of  the  Dorema  ammo- 
niacum. 

Assafoetida,  a  gum  resin  obtained  by  incision  from 
the  living  root  of  the  Narthex  assafoetida. 

Gamboge,  obtained  from  the  Garcinia  morella. 

Galbanum,  from  the  Ferula  galbaniflua. 

Myrrh,an  exudation  of  the  JSalsamodendronmyrrha. 

BALSAMS. 

Benzoin,  obtained  from  incisions  of  the  bark  of 
Sty  rax  benzoin. 

Balsam  of  Peru,  from  the  Myroxylon-Pereiroe,. 

Balsam  of  Tolu,  obtained  from  incisions  of  the  bark 
of  Myroxylon  toluifera. 


Caoutchouc  is  the  hardened  juice  of  Fious  elastica^ 
Jatropha  elastica,  Sipltonia  Gahuchu,  and  other  plants. 

Gutta-percha  is  the  concrete  juice  of  the  percha 
(Malay)  tree  the  Isonandra percha,  a  sapotaceous  plant. 


44  ORGANIC     CHEMISTRY. 


ALCOHOLS. 

GENERAL  DEFINITION  AND  CHARACTERISTICS. 

This  name  is  given  to  a  class  of  neutral  bodies  as 
important  as  they  are  numerous.  Their  essential 
characteristic  is  that  of  reacting  upon  acids  so  as  to 
form  water  and  a  class  of  bodies  called  ethers. 

The  number  of  alcohols  is  very  considerable.  There 
are  several  distinct  varieties  of  alcohol  recognized. 

I.  Those  built  on  the   type  of  one  molecule  of 
water: 

2iT5    [  O,  ethyl  or  common  alcohol. 

II.  On  two  molecules  of  water  : 

fr\  TT  /  /    -I 

Vr4      [  O2,  ethylene  alcohol  or  glycol. 

III.  On  three  molecules  of  water  : 

C1  TT  ' ' '  ) 

3Ty;         >  O3,  glycerine  and  thus  on. 
JJ-3        j 

They  may  be  defined  as  bodies  built  on  the  type  of 
one  or  more  molecules  of  water  having  one-half  of  the 
hydrogen  replaced  by  a  hydrocarbide  radicle. 

MONATOMIC    ALCOHOLS, 

or  those  formed  on  the  type  of  one  molecule  of  water, 


ALCOHOLS.  45- 

of  which  ordinary  alcohol  is  the  best  studied,  are 
characterized  by  the  fact  that  they  contain  one  atom 
of  oxygen  only,  and  that  by  reaction  with  the  mono- 
basic acids  they  form  but  a  single  ether. 

They  may  be  obtained  synthetically,  as  well  as  by 
various  indirect  processes. 

Subjoined  is  a  classified  list  of  the  more  important 
monatomic  alcohols: 

FIRST    SERIES, 


Methyl  alcohol  (wood  spirit),  C  H4  O 
Ethyl  alcohol,  (spirit  of  wine)  C2  H6  O 

Propyl  alcohol  C3  H8  O 

Butyl  alcohol,  -     C4Hi0O 

Amyl  alcohol,  C5  H12O 

Setyl  alcohol  -     C6H14O 

Octyl  alcohol  C  8H18  O 

Sexdecyl  alcohol  -     CjeH^O 

Ceryl  alcohol  C^Hgg  O 

Myricyl  alcohol    -  -     CsoH^  O  . 


SECOND    SERIES, 

CDH,nO. 

Vinyl  alcohol  C2  H4  O 

Allyl  alcohol  -      C3  H6  O. 

THIKD    SERIES, 

CnH2n_2O. 
Borneol  alcohol  -         C10H18O 


46  ORGANIC     CHEMISTRY. 

FOUKTH    SERIES, 

O.HM0. 

Benzyl  alcohol  C7  H8  O 

Xylyl  alcohol  -     C8  H10O 

Cumol  alcohol  C9  H12O 

Oymol  alcohol  -                   -  C10HU  O  . 

FIFTH    SERIES, 
CnH2n_8O. 

Cinnyl  alcohol  C9  H10O 

Cholesteryl  alcohol  -   C^  H^O  . 

MONATOMIC  ALCOHOLS  HAVING  THE  GENERAL  FORMULA, 


METHYL    ALCOHOL,    OR    WOOD-SPIRIT. 


CH40  =       3    O. 

This  substance  is  found  in  the  liquid  obtained  on 
distilling  wood.  The  distillate  contains  in  addition, 
water,  acetic  acid,  tar,  and  various  oils.  In  order  to 
extract  the  methyl  alcohol,  it  is  again  distilled  and 
that  portion  which  passes  over  at  90°  is  collected  ;  this 
is  diluted  with  water,  the  oil  which  precipitates  sepa- 
rated, and  the  liqiiid  agitated  for  a  considerable  time 
with  olive  oil.  This  oil  is  then  removed,  the  liquid 
redistilled  several  times  and  only  that  portion  collected 
which  passes  over  above  70°.  On  being  again 


ALCOHOLS.  47 

distilled  with  calcium  chloride  it  furnishes  methyl  al- 
cohol, nearly  pure,  boiling  at  66.5°. 

There  are  other  methods  of  rectifying  besides  the 
one  here  given. 

This  body  possesses  most  of  the  general  properties 
of  ordinary  alcohol.  Under  the  action  of  the  oxides  it 
furnishes  an  aldehyd  and  formic  acid. 

With  the  acids  it  produces  ethers;  viz.,  with 

CPI  / 

hydrochloric  acid,  methyl  chloride,  CH3C1=  p,3  /- ; 

with  acetic  acid, 

r1  TT 

methyl  acetic  ether,  C3H6O2=p  TT3Q  (•  O. 

CHLOROFORM,    CIIC]3 . 

Methyl  chloride  produces  with  chlorine  a  regular 
series  of  products  of  substitution.  One  of  these  terms, 
CHC13 ,  is  the  very  important  body,  chloroform,  dis- 
covered in  1831  by  Soubeiran  and  Liebig. 

To  prepare  this  compound,  40  litres  of  water,  5  kilos 
of  recently  slacked  lime,  arid  10  kilos  of  chloride  of 
lime  are  heated  to  40°;  1500  grams  of  90  per  cent, 
alcohol  are  then  added  and  the  retort  luted  with  clay. 

It  is  now  heated  for  a  moment  to  the  boiling  point 
and  the  fire  then  at  once  slackened. 

The  ebullition  having  ceased  there  will  be  found  two 
layers  in  the  receiver.  The  upper  layer  is  formed  of 
water  and  alcohol,  the  lower  one  is  chloroform  nearly 
pure.  The  latter  is  washed  with  water,  agitated  with 
a  dilute  solution  of  potassium  carbonate,  or  with  fused 


48  ORGANIC     CHEMISTRY. 

calcium  chloride  for  twenty-four  hours,  and  distilled 
to  four-fifths. 

Chloroform  is  a  colorless  liquid.  When  first  pre- 
pared it  has  a  sweetish  penetrating  taste,  and  an  agree- 
able, ethereal  odor. 

Its  density  is  1.48;  it  boils  at  60.5°,  is  soluble  in 
alcohol  and  ether  and  difficultly  so  in  water. 

It  burns,  though  not  readily;  its  flame  having  a 
green  margin.  It  dissolves  iodine,  sulphur,  phos- 
phorus, fatty  substances  and  resins. 

An  alcoholic  solution  of  potassa  decomposes  it  into 
chloride  and  formiate : 

CHC13  +  4KHO  =  3KC1  +  CHKOa  +  2H2O. 
PHYSIOLOGICAL  ACTION. 

Chloroform  is  at  present  very  generally  used  as  an 
anesthetic.  Opinions  as  to  its  manner  of  acting  are 
divided.  Formerly  it  was  thought  that  the  insensi- 
bility produced  was  the  commencement  of  asphyxia. 
Since  then  it  has  been  ascertained  that  the  heart,  in 
case  of  poisoning  by  chloroform,  immediately  loses  all 
power  of  contraction,  and  it  is  now  generally  admitted 
that  paralysis  of  the  muscles  and  nerves  of  the  heart  is 
produced. 

As  the  vapor  of  chloroform  is  very  dense,  care  should 
be  taken  that  in  its  use,  access  of  air  to  the  lungs  be 
not  wholly  prevented,  or  serious  consequences  may  re- 
sult. Probably  the  fatal  accidents  that  have  occurred 


ALCOHOLS.  49 

may,  in  some  instances  at  least,  be  attributed  to  lack 
of  care  in  this  regard. 

It  is  of  great  importance  that  the  chloroform  used 
should  be  quite  pure.  In  some  cases  it  lias  been  found 
to  have  undergone  spontaneous  decomposition  after 
exposure  to  a  strong  light.  It  ought  to  communicate 
no  color  to  oil  of  vitriol  when  agitated  with  it.  The 
liquid  itself  should  be  free  from  color  or  any  chlorous 
odor.  When  a  few  drops  are  allowed  to  evaporate  on 
the  hand  no  unpleasant  odor  should  remain. 

Shuttleworth  (100,  4,  339)  states  that  partially  de- 
composed chloroform  can  be  rectified  by  agitating  it 
with  a  solution  of  sodium  hypo-sulphite. 


ORDINAKY  ALCOHOL. 

ETHYLIC,  OR  VINIC  ALCOHOL. 

Formula:  CaHeO. 
Density  of  vapor  23. 
Density  .81. 
Boils  at  78.4o. 
Cannot  be  solidified. 

It  is  prepared  by  the  fermentation  of  saccharine 
liquids  at  a  temperature  of  25°  to  30°,  in  the  presence 
of  a  small  quantity  of  a  ferment.  Cane  sugar  does 
not  directly  become  alcohol  under  the  influence  of  a 
ferment.  It  is  first  transformed  into  two  other  sugars, 
glucose  and  levulose. 


50  ORGANIC     CHEMISTRY. 

C12HS8011+ H20-CflHl,06+C6H1A. 

Glucose.  Levulose. 

In  its  final  fermentation  nearly  all  the  sugar  is 
changed  into  alcohol  and  carbon  dioxide, 

C6H2Oy=2C,H60+4CO2. 

This  equation  accounts  for  the  transformation  of  94 
to  96  per  cent,  of  the  sugar  employed,  but  besides 
alcohol  and  carbon  dioxide,  succinic  acid  is  always 
formed  as  well  as  glycerine,  and  in  most  cases  "  fusel 
oil,"  consisting  chiefly  of  amyl  alcohol. 

Fermentation  is  a  phenomenon  correlative  with  the 
development  and  growth  of  cells  of  the  fungus  Myco- 
der/na  (Torula)  cerevisiw  which  constitutes  yeast. 
Sometimes  the  sugar  is  furnished  as  a  natural  product 
by  fruits ;  often  glucose  is  produced  from  the  starch 
of  cereals,  potatoes,  etc.,  and  then  changed  into  alcohol 
afterwards.  Corn  is  the  leading  original  source  in 
this  country. 

Alcohol  obtained  by  fermentation  is  concentrated 
by  distillation.  This  operation  is  performed  in  retorts, 
the  construction  of  which  is  based  upon  a  principle 
developed  by  A.  de  Montpellier,  and  improved  by 
Derosne,  Dubrunfaut  and  others.  The  object  is  to 
prevent  the  distilling  over  of  the  water  with  the  aVo- 
hol,  and  is  quite  well  accomplished  by  the  improved 
methods  now  employed.  The  details  are  not  suited 
to  the  scope  of  this  work. 

Thu  application  of  this  rational  method  of  distilling 


ALCOHOLS.  51 

admits  of  obtaining  liquids  containing  up  to  90  per 
cent,  of  alcohol,  but  it  is  difficult  to  go  beyond  that 
point  of  concentration. 

In  order  to  prepare  alcohol  more  concentrated,  sub- 
stances having  a  great  avidity  for  water  must  be  used. 
Calcium  chloride  is  not  suitable,  as  it  unites  with 
the  alcohol.  Anhydrous  sulphate  of  copper,  carbon- 
ate of  potassium  or  quicklime  do  not  produce  absolute 
alcohol.  But  it  is  very  rare  that  perfectly  anhydrous 
alcohol  is  required.  Alcohol  of  97  per  cent,  is  obtained 
in  treating  alcohol  of  85  per  cent,  during  two  days  with 
lime,  or  better,  with  a  sixth  or  seventh  part  of  its  weight 
of  dry  potassium  carbonate,  and  then  distilling.  If  it 
is  desired  to  procure  absolute  alcohol,  very  concen- 
trated alcohol  is  treated  with  caustic  baryta  until  the 
liquid  is  colored  yellow  and  then  distilled. 

Alcohol  in  fresh  bread  made  with  yeast  has  been 
found  by  Bolas  (S-27-271)  to  the  amount  of  .314  per 
cent.  Slices  of  bread  a  week  old  contained  .12  to  .13 
per  cent. 

Absolute  alcohol  is  a  colorless  liquid,  more  limpid 
than  water,  of  an  agreeable  odor  and  a  burning  taste. 
It  boils  at  78.4°,  is  neutral,  combustible  and  burns 
with  a  flame  but  little  luminous.  It  heats  on  coming 
in  contact  with  water,  and  attracts  the  moisture  of  the 
air  very  rapidly. 

It  contracts  upon  mixing  with  water;  the  max- 
imum of  contraction  takes  place  at  a  temperature  of 
15°  when  52.3  vol.  of  absolute  alcohol  are  mixed 
with  47.7  vol.  of  water;  instead  100  vol.  one  obtains 


52  ORGANIC     CHEMISTRY 

96.3   vol.     At  the  moment  of  admixture  numerous 
air  bubbles  escape  and  the  mixture  becomes  heated. 

The  alcoholic  strength  of  the  liquids  consumed  as 
beverages  varies  considerably. 

Madeira  wines,  about  20  per  cent. 

Malaga  "         "14  to  16 

Bordeaux  "         "15  to  12  " 

Ehine  "      10  to  12  " 

California  "         "      10  to  16  « 

Cider  2  to    7  " 

Beer  1  to    8 

Spirits  are  distilled  from  fermented  liquids;  brandy 
from  wine  ;  vshisky  from  a  mash  of  corn  or  rye  ;  rum 
from  molasses,  etc.  They  contain  about  50  per  cent, 
of  alcohol. 

The  term,  proof  spirits  was  originally  given  to  al- 
cohol sufficiently  strong  to  fire  gunpowder  when 
lighted.  The  strength  of  proof  spirits  now  varies  in 
different  localities,  and  it  would  be  well  were  this 
ambiguous  designation  no  longer  employed. 

Alcohol  dissolves  the  caustic  alkalies,  certain  ni- 
trates, chlorides  and  other  salts,  also  various  gases. 
"With  some  of  these,  genuine  chemical  combinations 
are  produced,  and  not  mere  solutions;  this  is  the  case 
with  calcium  chloride  and  magnesium  nitrate. 
Alcohol  can  be  mixed  with  ether  in  all  proportions; 
it  dissolves  the  resins,  essential  oils,  and  a  great  num- 
ber of  other  organic  bodies. 

The  chemical  properties  of  alcohol  are  very  inter- 


ALCOHOLS.  53 

«sting.  Yapor  of  alcohol  is  decomposed  on  passing 
through  a  tube  heated  to  redness;  hydrogen,  marsh- 
gas,  oxide  of  carbon,  small  quantities  of  naphthalin, 
benzol,  and  phenol  are  formed.  In  presence  of  air 
and  water  it  slowly  oxidizes  and  yields  acid  com- 
pounds. This  action  is  rapid,  if  a  hot  spiral  of  plati- 
num is  placed  in  the  alcoholic  vapor. 

EXPERIMENT. — Place  a  small  platinum  spiral  in  the 
wick  of  an  alcohol  lamp,  light  and  then  blow  out  the 
flame.  It  will  be  seen  that  the  spiral  remains  incan- 
descent. Spongy  platinum  acts  still  more  energetically; 
if  very  concentrated  alcohol  is  poured  drop  by  drop  into 
a  capsule  containing  spongy  platinum,  or  platinum 
black,  it  will  be  seen  to  redden,  fumes  are  produced  and 
an  acid  liquid  is  formed  containing  chiefly  aldehyd 
and  acetic  acid.  The  same  oxidation  occurs  if  diluted 
alcohol  is  exposed  to  the  air  in  the  presence  of  mother  of 
vinegar,  a  cryptogamic  plant,  (Mycoderma  aceti).  In 
fact,  this  is  the  basis  of  the  manufacture  of  wine-vin- 
egar and  alcohol. 

Fuming  nitric  acid  reacts  upon  alcohol  with  ex- 
plosive energy.  Aldehyd  is  formed,  also  acetic  ether, 
nitrous  ether  and  acetic,  formic,  glycollic,  oxalic  and 
carbonic  acids.  Alkaline  hydrates  attack  alcohol  even 
in  the  cold  potassium  acetate  being  the  chief  product 
formed.  If  alcoholic  vapor  is  made  to  pass  over  lime 
heated  to  250°,  hydrogen  gas  and  calcium  acetate 
are  produced;  the  latter  is  decomposed  at  a  more 
elevated  temperature  into  marsh  gas  and  water.  If 
silver  or  mercury  is  dissolved  in  nitric  acid,  and 
.90  per  cent,  alcohol  added  to  the  cooled  solutions,  a 


54  ORGANIC    CHEMISTRY. 

lively  ebullition  results,  and  a  crystalline  precipitate  is 
deposited  which  explodes  at  185°,  or  by  percussion. 
This  body  is  the  fulminate  of  silver  or  mercury,  re- 
spectively, which  is  considered  as  derived  from  methyl 
cyanide,  CH3Cy,  by  the  substitution  of  1  molecule  of 
nitryl,  and  of  1  atom  of  mercury,  or  2  of  silver  for  3 
atoms  of  hydrogen.  The  formulae  are  C(N02)HgCy; 
C(N02)Ag2Cy. 

Potassium  attacks  absolute  alcohol,  and  is  dissolved 
liberating  hydrogen;  on  cooling,  potassium  ethylate  is 
deposited.  Sodium  acts  in  the  same  manner.  These 
compounds,  if  brought  in  contact  with  water,  regenerate 
alcohol  and  the  respective  alkaline  hydrates. 

Acids  attack  alcohol  and  furnish  compound  ethersr 
which  we  will  study  later.  Ozone,  according  to  A.  W. 
Wright,  (80 — [3]7 — 184)  oxydizes  alcohol  to  acetic  acid. 

PHYSIOLOGICAL  ACTION"  OF  ALCOHOL.  USES  OF  AL- 
COHOL.—Alcohol  coagulates  the  blood;  injected  into  the 
veins  it  produces  instantaneous  death.  It  is  a  very 
powerful  poison,  as  are  all  alcohols  of  the  series 
CnHan+aO.  Rabuteau  (9—81—631)  has  shown  that 
they  are  more  poisonous  in  proportion  as  their  mole- 
cules are  complex.  Cases  have  been  observed  where  a 
large  dose  of  alcohol  has  caused  death  in  half  an  hour. 

The  worse  than  worthless  character  of  distilled 
liquors  as  beverages  is  no  longer  an  open  question. 
With  regard  to  their  value  as  food  or  medicine,  a  more 
authoritative  or  competent  expression  of  opinion  can- 
not be  desired  than  that  of  the  International  Medical 
Congress,  which  at  its  session  in  Philadelphia  in  1876, 
said: 


ALCOHOLS.  OO 

"1.  Alcohol  is  not  shown  to  have  a  definite  food 
value  by  any  of  the  usual  methods  of  chemical  analy- 
sis or  physiological  investigation. 

"  2.  Its  use  as  a  medicine  is  chiefly  that  of  a  cardiac 
stimulant,  and  often  admits  of  substitution. 

"  3.  As  a  medicine,  it  is  not  well  fitted  for  self-pre- 
scription by  the  laity,  and  the  medical  profession  is 
not  accountable  for  such  administration,  or  for  the 
enormous  evils  arising  therefrom. 

"  4.  The  purity  of  alcoholic  liquors  is,  in  general, 
not  as  well  assured  as  that  of  articles  used  for  medicine 
should  be.  The  various  mixtures  when  used  as  medi- 
cine, should  have  definite  and  known  composition,  and 
should  not  be  interchanged  promiscuously." 

The  dissolving  power  of  alcohol  renders  it  very  ser- 
viceable in  the  arts.  Solutions  in  this  menstruum  are 
called  alcoholic  tinctures.  Only  the  purest  alcohol 
ought  to  be  used  in  pharmacy,  though  of  course,  various 
strengths  are  requisite,  as  it  should  be  of  a  degree  to 
suit  the  nature  of  the  matter  to  be  dissolved.  If  the 
substance  to  be  treated  is  a  resin,  or  some  substance 
absolutely  insoluble  in  water,  a  very  concentrated  alco- 
hol is  preferable.  A  weaker  alcohol  is  made  use  of,  if 
the  matter  is  one  that  is  soluble,  both  in  alcohol  and 
water. 

Alcohol  acts  not  only  as  a  solvent,  but  also  as  a  pre- 
ventative  of  decay.  This  is  a  property  which  renders 
it  especially  valuable  in  the  preparation  of  remedies.  . 


56  ORGANIC    CHEMISTRY. 

AMYL  ALCOHOL. 

C5IIiaO  =  C5HU  }  Q 
H    f°- 

Synonyms:     FOUSKL  (OK  FUSEL)  OIL,  POTATO  SPIRIT. 

The  amylic  compounds  derive  their  name  from 
Amylum,  starch,  the  chief  constituent  of  the  potato. 
They  are  formed,  in  some  proportion  in  almost  every  in- 
stance of  alcoholic  fermentation  of  sugar.  Amylic 
alcohol  is  usually  prepared  on  fractionally  redistilling 
the  oil  which  remains  when  the  alcohol,  prepared 
from  potatoes,  barley,  corn,  etc.,  is  distilled.  The  pro- 
duct which  comes  over  at  132°,  is  that  collected. 
Cahours  and  Balard  first  established  the  analogy,  in 
constitution  and  properties,  of  this  compound  with 
ordinary  alcohol.  It  is  a  monatomic  alcohol,  giving 
with  oxidizing  re-agents,  valeric  acid. 

C5IIteO+O3  =  C5H1(A+H,O, 

Amylic  alcohol.  Valeric  acid. 

and  with  acids,  compound  ethers,  as 

Chloride  of  amyl,  CSHHC1. 

C-II      ) 
Acetate  of  amvl  or  amyl-acetic  ether,        r^rVK  -  ^« 

VA,  lT;jl  /    \ 


ALCOHOLS.  57 

MON  ATOMIC  ALCOHOLS. 
Having  the  general  Formula  CnH2nO. 

ALLYLIC  ALCOHOL,  C3H6O  =  C3H5 

H 

This  is  a  body  giving  the  same  reactions  as  ordinary 
alcohol.  The  radicle  it  contains  is  the  same  as  that 
in  the  triatomic  alcohol,  glycerine.  Among  its  deriva- 
tives there  are  two  which  are  of  considerable  impor- 
tance : 

Allyl  sulphide,  S3^5  i  S. 

^stis  } 

Sulpho-cyanide,  £j3^5  j-  S. 

The  former  is  oil  of  garlic;  the  latter  oil  of  mustard. 
OIL  OF  GAELIC  is  prepared  by  the  following  method: 
allylic  alcohol  is  treated  with  phosphorus  iodide  which 
furnishes  allyl  iodide  C8H5I.  This  iodide  is  afterwards 
mixed  with  an  alcoholic  solution  of  potassium  sulphide 
and  the  whole  is  distilled;  the  product  which  passes 
over  is  identical  with  the  essential  oil  obtained  in  dis- 
tilling garlic,onions,  assafoetida,  etc.,  with  water. 

OIL   OF    MUSTARD,    OR    SULPHO-CYANIDE    OF    ALLYL. 

This  body  is  prepared  by  causing  iodide  of  allyl  to 
react  upon  potassium  sulpho-cyanide,  TT-  >•  S,  and  may 

C\  ) 
be  regarded  as  sulplio-cyanic  acid,    rj  ?•  S,  having  the 


58  ORGANIC     CHEMISTRY. 

hydrogen  replaced  by  the  radicle  of  allyl  alcohol,  C3TT5. 
The  product  which  distills  over  is  an  irritating  liquid 
which  boils  at  145°,  like  the  oil  prepared  from  mus- 
tard directly.  This  substance  may  also  be  obtained 
by  the  action  of  allylic  alcohol  upon  potassium  sul- 
pho-cyanide.  It  is  likewise  obtained  by  the  fermenta- 
tion of  mustard  seeds. 

Sulpho-cyanide  of  allyl  does  not  exist  already  formed 
in  black  mustard  (Sinapis  nigra\  but  according  to 
Bussy,  its  formation  is  due  to  a  particular  ferment. 

Oil  of  mustard  combines  directly  with  ammonia, 
forming  a  crystalline  substance  called  thiosinna/mine, 
C.tHgl^S,  which,  in  contact  with  mercuric  oxide, 
changes  into  an  alkaloid  called  sinnamine,  of  which 
the  composition  is  C4H6N2.  It  reacts  upon  lead  oxide 
producing  a  substance  called  sinapoline  whose  formula 
is  C7HiaN2O. 

BORNEO   CAMPHOR,    OR    BORNEOL    CjoHigO. 

This  body  exudes  from  \\\^Dryobalanops  campkora 
(Borneo).  It  is  crystalline  and  has  an  odor  between 
that  of  camphor  and  pepper.  It  fuses  at  195°,  and 
boil  sat  about  220°.  It  is  dextrogyrate.  Heated  with 
nitric  acid  it  furnishes  common  camphor  C]0Hi6O. 

DIATOMIC    ALCOHOLS  OR  GLYCOLS. 


Ordinary  Glycol,  (C2H4)  —  0,—  H2=C,H6O, 
Propyl  "      (C3H6)  —  02~—  H2=<1,H8O, 


ALCOHOLS. 

Butyl  Glycol,  (C4H8)  —  02— H^C.H,  002 

Arnyl        "  (C5H10)-02-H2=C5H1208 

Hexyl       "  (C6H12)-02-H2=C6H1402 

Octyl        "  (C8H16)-02— H2=C8H1802. 

TRIATOMIC    ALCOHOLS. 

Glycerine,  (C3H5)-03-H3=C3H803. 

TETRATOMIC    ALCOHOLS. 

Erythrite,  (C4H6)— 04— H4=C4H1004. 

OTHER    COMPLEX   ALCOHOLS. 

Glucose  and  its isomerides,  (C 6 H 6) — 0 6  — H 6=C6H1206, 
Mannite,  -      (C6H8)-06-H6=C6H1406. 

Dulcite,  -    (C.H8)-06-H.=C6H1408. 

Quercite,  I  p  TT  n  j_  (CH.,)2  (.n  _i_r  TT    r» 

Pinnite,  \<-3ti*O  -f      H,     ^2+C6H1206. 

ORDINARY    GLYCOL. 

r  IT  o  =(^"-2)2  '  n 

v-'sJigUa          £.j      (  ^2- 

The  discovery  of  the  glycols  was  an  event  of 
great  importance.  It  was  achieved  by  Wurtz  in  1856, 
and  the  glycol  of  which  we  are  treating  was  the  first 
discovered. 

In  a  flask  surmounted  by  a  condenser,  two  parts  of 
potassium  or  sodium  acetate,  are  dissolved  in  weak 
alcohol  and  one  part  of  ethylene  bromide  added.  This 


tjO  ORGANIC    CHEMISTRY. 

mixture  is  heated  in  a  water  bath  as  long  as  the 
cipitate  of  alkaline  bromide  continues  to  form,  care 
being  taken  at  the  same  time  to  keep  the  worm  well 
cooled,  in  order  that  the  vapors  of  alcohol  may  contin- 
ually flow  back  into  the  flask.  T.he  alcohol  is* distilled 
off  in  a  water  bath,  and  the  residue  afterwards  also 
distilled  at  a  higher  temperature,  and  that  part  col- 
lected which  passes  over  between  140°  and  200° .  This 
portion  which  contains  monacetic  glycol,  is  heated 
with  a  saturated  solution  of  baryta  until  the  liquid 
acquires  a  strong  alkaline  reaction.  The  excess  of 
baryta  is  removed  by  passing  carbon  dioxide  through 
the  solution  which  is  then  filtered  and  evaporated. 
The  barium  acetate  is  precipitated  completely  by  strong 
alcohol,  and  the  alcohol  subsequently  removed  by  dis- 
tillation. The  retort  is  now  heated  in  an  oil  bath,  and 
that  portion  set  aside  which  boils  above  150°.  This  is 
redistilled  and  the  distillate  between  190°  and  198° 
is  the  product  sought.  Zeller  and  Huefner  have  lately 
(18,  10,270)  obtained  the  purest  glycol  by  simply  heat- 
ing a  solution  of  potassium  carbonate  with  ethylene 
bromide. 

Glycol  is  a  colorless,  odorless  liquid,  somewhat 
viscid  and  having  a  sweetish  taste.  Its  density  is 
LI 2;  water  and  alcohol  dissolve  it  in  all  proportions. 
Ether  dissolves  it  with  difficulty. 

It  is  not  oxydized  in  the  air  under  ordinary  con- 
ditions, but  if  dilute  glycol  be  made  to  fall  on  plati- 
num black,  it  becomes  heated  and  is  transformed  into 
fjly  colic  acid.  Itsequi valence  is  shown  by  the  follow- 


ALCOHOLS.  61* 

ing  :    glycol    attacks    sodium    forming  two    sodiuma 
glycols; 

C2  H4  )  f-v  C2H4  )  ^ 


These  glycols  furnisli  two  ethyl  glycols  on  being 
heated  with  ethyl  iodide. 


C2H5,H  f  "*>  (C2H5)2  r  °* 

Ethyl-glycol.  Diethyl-glycol. 

With  hydrogen  bromide  it  furnishes  two  different 
products  according  to  the  number  of  molecules  of  HBr 
taken. 

CSHA+  HBr  =  C2H5BrO  +  H2O. 

Monobromhydric 
ether. 

C^  TT  f~\       i     f)TTT?-M — r^  TT  T>m  I     f)TT  /~\ 
Vy'2-tlgL'2      I      iJlJDr — Vx'2Ji4jt3I2l      AlJL^J. 

Ethylene 
bromide . 

It  is  evident  that  mixed  ethers  may  be  obtained  by 
treating  glycol  not  with  two  molecules  of  the  same 
acid,  but  with  two  molecules  of  different  acids.  Thus 

0  TT  ) 

aceto-chlorhydric  glycol  is  formed  //-,  TT  c\\r>\  r  O. 


62  ORGANIC    CHEMISTRY. 

These  ethers,  in  the  presence  of  alkalies,  are  re- 
formed into  their  respective  acids  and  glycol,  in  the 
same  manner  in  which  ethers  of  ordinary  alcohol 
regenerate  alcohol. 

Monochlorhydric  and  aceto-chlorhydric  glycol  form 
an  exception  to  this  rule ;  they  form  oxide  of  ethylene 
in  presence  of  alkalies. 

OXIDE  OF  ETHYLENE,   C2H4O, 

a  polymer  of  (C2H4)2O2,  is  related  to  glycol  as  ordinary 
ether  to  alcohol.  It  is  not  obtained  like  the  latter  by  the 
action  of  hydrogen  sulphate  on  the  alcoholic  compound, 
but  is  produced  by  the  action  of  potassa  on  mono- 
chlorhydric  glycol.  A  solution  of  potassa  is  gradually 
poured  into  chlorhydric  glycol  placed  in  a  glass,  or  a 
tubulated  retort. 

KHO  +  C8H6C10  =  KC1  +  H80  -f  C2H40. 

The  oxide  of  ethylene  distills  over  with  the  water; 
the  latter  is  absorbed  by  causing  the  vapors  to  pass 
through  a  flask  containing  anhydrous  calcium  chloride, 
and  the  oxide  is  condensed  in  a  receptacle  placed  in  a 
refrigerating  mixture. 

It  is  a  colorless,  ethereal,  fragrant  liquid;  boiling  at 
13°.  Its  density  is  0.89.  Ethylene  oxide  is  very  solu- 
ble in  water,  alcohol  and  ether.  It  burns  with  a  lumin- 
ous flame  and  reduces  silver  salts.  It  has  the  compo- 
sition but  not  the  properties  of  aldehyd,  of  which  it  is 
;m  isomeride. 


ALCOHOLS.  63 

Oxide  of  ethylene  is  a  very  remarkable  body.  It 
combines  directly  with  oxygen,  hydrogen,  chlorine  and 
bromine,  also  combines  directly  with  acids,  often  even 
with  the  disengagement  of  heat,  forming  the  ethers  of 
glycol  and  polyethylenic  alcohols.  This  body  is  there- 
fore a  true  non-nitrogenous  basic  oxide. 


64  ORGANIC    CHEMISTRY. 


TEIATOMIC  ALCOHOLS  OR  GLYCERINES. 

C    Hr     ) 

ORDINARY  GLYCERINE,  C3H8O3  =       rT5  ,-  O   . 

-"•3    ) 

This  body,  discovered  by  Scheele,  in  1779,  and 
called  by  him,  on  account  of  its  sweet  taste,  the  sweet 
principle  of  oils,  has  been  specially  studied  by  Chevreul 
and  by  Pelouze.  Berthelot  discovered  its  real  nature 
and  proved  it  to  be  a  tri atomic  alcohol. 

Glycerine  is  prepared  by  decomposing  neutral 
fatty  bodies,  in  the  soap  and  candle  industry  by  alka- 
lies, or  better  still  by  superheated  steam.  (Tilghman'a 
process.}  It  is  obtained  in  pharmacy,  whenever  lead 
plaster  is  prepared  and  remains  in  the  water  with 
which  the  latter  is  washed. 

It  is  much  employed  in  pharmacy  and  perfumery 
and  as  a  solvent  for  many  substances.  Crude  glycer- 
ine may  be  purified  by  boiling  with  animal  charcoal 
and  filtering  before  being  evaporated  to  the  required 
consistency.  The  best  process  consists  in  distilling  the 
crude  condensed  glycerine  in  a  current  of  steam.  Pas- 
teur has  shown  that  glycerine  is  produced  in  a  very 
small  quantity  in  alcoholic  fermentation.  "We  owe  to 
Wurtz,  a  remarkable  synthetical  reproduction  of  glycer- 
ine. Propylene  C3H6  furnishes  an  iodide  C3H3I,  called 
iodide  of  allyl.  This  body  produces  with  bromine  the 


ALCOHOLS.  65 

compound   C3H3Br3  which,    treated   with  potassa,   or 
oxide  of  silver,  yields  glycerine. 

C3H5Br3+3KHO  =  3  KBr.+C3H8O3. 

Glycerine  . 

Glycerine  is  a  synipy  liquid,  colorless,  of  a  sweetish 
taste  and  destitute  of  odor;  its  density  is  1.28  at  15°. 
Sarg  has  obtained  crystals  of  glycerine,  whose  angles 
have  been  measured  by  Victor  Lang  (2-1  52-63  Y). 
They  are  rhombic  in  form  and  very  deliquescent.  Glyc- 
erine is  soluble  in  alcohol  and  water  in  all  propor- 
tions; it  is  not  dissolved  by  ether.  It  dissolves  alka- 
lies, alkaline  sulphates,  chlorides  and  nitrates,  copper 
sulphate,  silver  nitrate  and  many  other  salts. 

Glycerine  distills  at  280°,  but  is  thereby  partially 
decomposed.  It  may,  however,  be  distilled  in  a 
vacuum  without  change.  It  is  decomposed  at  a  tem- 
perature above  300°,  and  oils,  inflammable  gases, 
carbon  dioxide,  and  a  product  very  irritating  to  the 
eyes,  called  acrolein,  acrylic  aldehyd,  are  formed  ; 
this  last  substance  may  be  obtained  pure  by  distilling 
glycerine  with  sulphuric,  or  phosphoric  acid.  The 
formula  of  acrolein  is  C3H4O,;  it  is  also  produced  in 
the  dry  distillation  of  all  fatty  bodies  which  contain 
glycerine.  If  glycerine  be  made  to  fall  drop  by  drop 
upon  platinum  black,  it  unites,  like  alcohol  and 
glycol,  with  O2  and  glyc&ric  acid  is  formed. 


C3H803  +  08=C8H604 

The  oxidation  of  the  glycerine  does  not  stop  here; 


66  ORGANIC     CHEMISTRY. 

there  is  subsequently  formed,  acetic,  formic,  and  car- 
bonic, but  chiefly  oxalic  acid.  The  action  of  acids  on 
glycerine  demonstrates  two  facts;  first,  that  glycerine 
is  an  alcohol;  second,  that  it  is  a  triatomic  alcohol. 
On  treating  glycerine  with  hydrochloric  acid  the  first 
reaction  is  similar  to  that  between  alcohol  and  this 
acid, 

HCl+C3II8O3^C3H7ClOo+H,O. 

Monochlorhydric  ether, 

or 
Monochlorhydriu. 

The  continued  action  of  phosphorous  perchloride 
upon  glycerine,  or  the  diclilorhydrate  of  glycerine, 
effects  the  elimination  of  additional  molecules  of  water 
and  the  formation  of  trichlorhydrin. 

3HC1+C;,HA=C3H5C1:!  +  3(11,0}. 

Trichlorhydrin. 

Berthelot  has  studied  the  acetines,  butyrines  (tri- 
butyrine  exists  in  butter),  valerines,  and  many  other 
ethers  of  glycerine.  If  glycerine  is  mixed  with  cold 
nitric  acid,  and  sulphuric  acid  added  drop  by  drop,  an 
oily  substance  separates  out  which  is  trinitroglycerine, 
C3H5(NOo)3O3.  This  body  detonates  with  great  vio- 
lence. It  acts  very  energetically  on  the  system.  A 
few  drops  placed  on  the  tongue  produce  violent  me- 
grim. Glycerine  forms  compounds  with  lime  anal- 
ogous to  those  formed  by  sugar,  according  to  P.  Car- 
les, (1-1T4-87). 


ALCOHOLS. 


67 


USES. — The  uses  of  glycerine  in  the  arts,  and 
especially  in  pharmacy,  are  numerous  and  important, 
many  of  which  are  based  upon  the  solvent  power  of 
this  compound.  Henry  "Wurtz  (31-195-58)  has  made 
valuable  suggestions  as  to  its  economical  applications. 

TABLE   SHOWING  THE   SOLUBILITY  OP    SOME    CHEMICALS   IK  GLYCERINE,   (FROM 

JSLEVER.)   ONE    HUNDRED   PARTS   OF  GLYCERINE   DISSOLVE   THE  ANNEXED 

QUANTITIES  OP    THE  FOLLOWING  CHEMICALS: 


Arsenous  oxide, 
Arsenic  oxide, 
Acid,  benzoic, 
"      oxalic, 
"      tannic, 
Alum, 
Ammonium  carbonate, 

"  chloride, 

Antimony  and  potassium  tartrate, 
Atropia, 

Atropia  sulphate, 
Barium  chloride, 
Brucia, 
Cinchonia, 

"          sulphate. 
Copper  acetate, 

"     sulphate, 

Iron  and  potassium  tartrate, 
"    lactate, 
"    sulphate, 
Mercuric  chloride, 
Mercurous  chloride, 
Iodine, 
Morphia, 
Morphia  acetate, 

"        chlorhydrate, 
Phosphorus, 
Plumbic  acetate, 
Potassium  arsenate, 
"  chlorate, 

"  bromide, 

"  cyanide, 

"  iodide, 


Quinia, 


taunate, 


20.00 

20.00 

10.00 

15.00 

50.00 

40.00 

20.00 

20.00 

5.50 

3.00 

33.00 

10.00 

2/25 

0.50 

6.70 

10.00 

30.00 

8.00 

16.00 

25.00 

7.50 

27.00 

1.90 

0.45 

20.00 

20.00 

0.20 

20.00 

50.00 

3.50 

25.00 

32.00 

40.00 

0.50 

0.25 


68  ORGANIC    CHEMISTRY. 

Sodinm  arsenate.  50.00 

"       bicarbonate,  8.00 

"       borate,  ttO.OO 

"      carbonate,  98.00 

"       chlorate,  20.00 

Sulphur,  0.10 

Strychnia,  0.25 

"           nitrate,  4.00 

"           sulphate,  22.50 

Urea,  50.00 

Veratria,  1-00 

Zinc  chloride,  50.00 

"     iodide,  40.00 

11     sulphate,  J5.00 


The  general  use  of  glycerine  in  pharmacy,  to  pre- 
vent solid  extracts  from  becoming  too  hard  by  evap- 
oration, is  greatly  to  be  deprecated,  as  an  adulterant 
is  thereby  introduced,  which  renders  this  class  of 
remedies  more  or  less  unreliable. 


ETHERS.  69 


ETHERS. 

SIMPLE    ETHEKS. 

Ethers  are  products  formed  by  the  action  of  alcohols 
upon  acids. 

Bv  most  chemists  they  are  looked  upon  as  referable 

to  the  oxides  of  metals  :  thus   ^rr3  >•  O  and  ^'rr5  :    O, 

O±ig  ^a-tLs  ) 


may  be  regarded  as  the  oxides  respectively  of  methyl 
and  ethyl.  They  bear  the  same  relation  to  alcohols 
that  oxides  of  the  metals  do  to  the  hydrates. 

Potassium  hydrate  KOH. 

Ethyl  hydrate,  or  ethyl  alcohol  C2H5OH. 

Potassium  oxide  ^  I  0. 

Ethyl  oxide  or  ethyl  ether  S- 

^2 

The  simple  ethers  are  mostly  liquid.  They  are  very 
slightly  soluble  in  water,  while  they  are  readily  soluble 
in  alcohol.  Exposed  to  the  action  of  alkaline  solu- 
tions they  regenerate  alcohol. 

C4H80,+KHO  =  C2H60+KC2H302. 


70  ORGANIC     CHEMISTRY. 

ETHYL    ETHER. 

Synonyms  :    Vinic  ether,  sulphuric  ether,  common  ether. 


Density  .736. 
Density  of  vapor,  37. 
Specific  gravity  of  vapor,  2.586. 
Boiling  point,  35.5°. 


To  prepare  this  compound,  sulphuric  acid  is  heated 
with  alcohol  in  a  retort,  placed  in  a  sand-bath.  The 
ether  distills,  its  vapor  being  received  in  a  well  cooled 
condenser,  provided  with  a  long  tube  which  conducts 
the  uncondensed  vapor  into  a  chimney. 

The  cork  adapted  to  the  tubulure  of  the  retort  is 
provided  with  two  openings;  in  one  is  fixed  a  ther- 
mometer, through  the  other  a  tube  passes  which  fur- 
nishes the  supply  of  alcohol.  All  the  connections 
should  close  perfectly.  When  the  apparatus  is  arranged 
in  this  manner,  pour  700  grams  of  85  percent,  or  90  per 
cent,  alcohol  into  the  retort,  and  add,  little  by  little,  100 
grams  sulphuric  acid  of  1.84 sp.  gr.,  then  heat.  When 
the  thermometer  attains  130°,  cause  the  alcohol  to 
flow  from  the  upper  vessel  at  a  rate  sufficient  to  keep 
the  temperature  between  130°  and  140°.  The  weight 
of  alcohol  capable  of  being  transformed  into  ether  is 
from  13  to  15  times  the  weight  of  the  mixture  first  in- 
troduced into  the  retort.  The  distilled  liquid  is  mixed 


ETHEKS.  71 

with  12  parts,  to  every  100  of  its  weight,  of  a  solution 
of  soda  having  a  specific  gravity  of  1.32,  and  agitated 
from  time  to  time,  during  48  hours. 

The  ether  is  decanted  by  means  of  a  glass  siphon, 
redistilled  and  four-fifths  of  the  liquid  collected.  The 
remainder  may  serve  for  a  future  operation. 

This  furnishes  ordinary  ether.  To  further  purify, 
wash  with  water,  decant  and  treat  for  two  days  with  equal 
parts  of  quick  lime  and  fused  calcium  chloride.  Wil- 
liamson has  clearly  shown  that  etherification  takes 
place  in  two  stages  or  successive  reactions  as  follows: 

C2HeO  +  H2S04  =  H20  +  (C2H5)HS04. 

Ethylsulphuric  acid. 

(C2Hg)HS04  +  C2H60  =  C4H100  +  H2SO4. 

This  explains  how  a  small  quantity  of  sulphuric 
acid  etherizes  a  large  amount  of  alcohol,  since  sul- 
phuric acid  is  constantly  regenerated.  This  is  con- 
firmed by  the  following  experiment.  Iodide  of  ethyl 
is  made  to  react  upon  potassium  alcohol ;  ether  is 
obtained  as  indicated  by  the  reaction; 

C2H5I  +  C2H5OK  =  C4H100  +  KI. 

Ether  is  a  neutral,  volatile  liquid,  colorless,  having  a 
burning  taste  and  a  strong  agreeable  odor.  When 
agitated  with  water  it  rises  to  the  surface,  but  the 
water  dissolves  about  one  ninth  of  its  own  weight  of 
the  ether.  It  is  miscible  Math  alcohol  in  all  propor- 


72  ORGANIC     CHEMISTRY. 

tions  and  with  wood  spirit.  Ether  is  frequently  adul- 
terated with  the  latter  substance.  Next  to  alcohol  it 
is  the  most  generally  employed  solvent  for  organic 
substances.  It  dissolves  resin,  oils  and  most  com- 
pounds rich  in  carbon  and  hydrogen. 

Bromine,  iodine,  chloride  of  gold  and  corrosive  sub- 
limate are  soluble  in  this  liquid.  It  dissolves  phos- 
phorus and  sulphur  in  small  quantity. 

W.  Skey  (8 — Aug.  3, ' 77,)  has  shown  that  contrary  to 
the  usual  statement  in  standard  works,  ether  dissolves 
notable  quantities  of  the  alkalies. 

At  a  red  heat  it  is  decomposed  and  furnishes  carbon 
monoxide,  water,  marsh  gas  and  acetylene. 

It  is  exceedingly  inflammable,  and  burns  with  a 
bright  flame. 

Its  extreme  volatility,  the  density  of  its  vapor,  its 
insolubility  in  water  and  its  great  inflammability  render 
its  use  dangerous,  and  explosions  caused  by  it  are  of 
frequent  occurrence.  It  should  never  be  brought  near 
a  fire  or  light  in  open  vessels.  In  case  ether  inflames, 
it  is  best,  if  possible,  to  at  once  close  the  vessel  con- 
taining it,  and  thus  avoid  the  more  serious  conse- 
quences ensuing  from  an  explosion.  Exposed  to  the 
air  it  experiences  a  slow  combustion  as  in  the  case  of 
alcohol,  and  the  same  compounds  are  the  result. 

Chlorine  acts  violently  upon  it;  in  moderating  the 
action,  the  whole  or  a  part  of  the  hydrogen  may  be 
replaced  atom  for  atom  by  chlorine. 

[TSES.—  It  is  used  in  pharmacy  in  preparing  etherial 


ETHERS.  73 

tinctures,  and  as  an  antispasinodic  and  stimulant  in 
the  well-known  Hoffmann's  anodyne.  Its  most  impor- 
tant use  in  medicine  is  as  an  anesthetic,  than  which 
none  is  safer  or  more  reliable  in  efficient  hands.  It 
is  extensively  employed  in  the  laboratory  and  in 
photography. 

COMPOUND    ETHERS 

are  bodies  built  up  on  the  type  of  water,  having  one 
half  the  hydrogen  replaced  by  a  hydrocarbide  and  the 
other  half  by  a  compound  radicle  containing  oxygen., 
or,  in  other  words,  by  the  radicle  of  an  acid. 

TO  IT  \ 
ACETIC  ETHER,  /r^Un 

^2risv 

To  prepare  this  ether  8  parts  of  very  concentrated 
alcohol  are  distilled  with  7  parts  of  sulphuric  acid  and 
10  parts  of  anhydrous  sodium  acetate,  which  may  be 
replaced  by  20  parts  of  dry  lead  acetate.  The  distil- 
late is  agitated  with  a  solution  of  calcium  chloride 
containing  milk  of  lime,  decanted,  dried  over  calcium 
chloride  and  finally  distilled. 

Seven  parts  of  water  dissolve  one  part  of  this  body. 
Alcohol  and  ether  dissolve  it  in  all  proportions.  It 
is  a  solvent  for  many  organic  bodies.  It  is  easily  de- 
composed on  contact  with  water.  Potassa  also  effects 
this  decomposition  very  readily.  A  prolonged  action  of 
ammonia  transforms  it  into  acetamide  and  alcohol. 


74  ORGANIC    CHEMISTRY. 

OXALIC    ETHERS. 

Oxalic  acid,  being  a  bibasic  acid,  furnishes  with 
alcohol  two  combinations,  one  being  acid  and  capable 
of  combining  with  bases  ;  the  other  is  neutral,  C6H10O4. 

Only  the  latter  is  of  interest.  It  may  be  prepared 
by  introducing  four  parts  of  90  per  cent,  alcohol  and 
four  parts  of  oxalic  acid  into  a  retort,  adding  to  thi& 
mixture  three  to  six  parts  of  sulphuric  acid  and  then 
rapidly  distilling  ;  the  product  is  washed  several  times,, 
dried,  then  redistilled,  collecting  only  the  liquid  which 
passes  over  at  184°.  This  ether  is  aromatic,  oily,  and 
gradually  decomposes  in  water. 

Potassium  changes  it  into  carbonic  ether. 

If  oxalic  ether  is  agitated  with  ammonia,  a  white 
powder,  oxamide,  and  ethyl  alcohol  are  produced. 


Oxamide  may  be  considered  as  derived  from  two 
molecules  of  ammonia,  and  belongs  to  a  class  of  bodies 
called  diamides. 

It  is  a  white  substance,  insoluble  in  cold  water  and 
alcohol.  Heated  with  mercuric  oxide  it  is  transformed 
iiito  carbon  dioxide  and  urea.  (Williamson.) 


ETHERS.  75 

Oxalic  ether  treated  with  ammonia  in  solution  in 
alcohol  furnishes  oxamic  ether. 

In  this  connection  the  compounds  of  the  organic 
radicles  with  the  haloid  elements  are  usually  studied: 
they  are  not  unfrequently  denominated  ethers  of  the 
hydracids.  Their  type  is  a  molecule  of 

TT 

hydrogen, 

CHLORIDE  OF  ETHYL  OK  CHLOKHVDKIC  ETHEB. 


p 

This  body  is  formed  in  small  quantity  when  ethy- 
lene  is  made  to  react  upon  hydrochloric  acid. 

To  prepare  it,  alcohol  contained  in  a  flask  sur- 
rounded by  cold  water,  is  saturated  with  hydrochloric 
acid  gas  and  the  mixture  then  distilled. 

C8H60+HC1=C8HBC1+H80. 

It  is  also  obtained  by  pouring  into  a  flask  contain- 
ing 2  parts  common  salt,  a  mixture  of  1  part  alcohol, 
and  1  part  sulphuric  acid  :  it  is  then  gently  heated 
and  the  ether  collected  as  previously  shown. 

It  is  a  liquid  of  an  agreeable  odor,  and  very  volatile, 
having  a  boiling  point  of  12°  and  a  vapor  density  of 
64°.  A  red  heat  decomposes  it  into  ethylene  and 
hydrochloric  acid  gas.  It  is  combustible  and  burns 
with  a  green,  smoky  flame  ;  water  dissolves  the  fif- 
tieth part  of  its  volume,  alcohol  dissolves  it  completely. 


76  ORGANIC    CHEMISTRY. 

With  chlorine  it  furnishes  a  complete  and  regular 
series  of  products  of  substitution  which  are  not  iden- 
tical, but  isomeric  with  the  chlorine  products  of 
ethene. 

Their  formulae  are: 

C2H4C12 

C3H3C13 

C2H3C14 

Crr    r\-\ 
2*1    ^5 

CP1 
2  I-'1  e- 

IODIDE   OF    ETHYL   OR    HYDROIODIO    ETHER. 

C,ILI  =  C^] 


is  obtained  on  causing  alcohol  to  react  upon  iodide  of 
phosphorus;  the  action  is  violent  with  white  phos- 
phorus, considerably  less  so  with  red  phosphorus. 

Six  hundred  grains  of  concentrated  alcohol  are  intro- 
duced into  a  retort  with  140  grains  of  amorphous 
phosphorus,  and  to  this  mixture  450  grams  of  iodine 
are  added.  The  distilling  is  carried  nearly  to  dryness. 
The  product,  condensed  in  the  receiver,  is  washed  with 
water  containing  a  little  potassa  ;  afterwards  with  pure 
water.  It  is  then  dried  over  calcium  chloride  and 
again  distilled. 

Iodide  of  ethyl  is  a  colorless  liquid.  Its  density  is 
1.975.  It  becomes  colored  on  exposure  to  light,  being 
slightly  decomposed  ;  it  is  again  rendered  colorless  on 
agitating  it  with  an  alkaline  solution,  which  absorbs  the 


ETHERS.  77" 

acid  formed.  It  burns  with  a  green  flame,  leaving  a  resi- 
due of  iodine.  Ammonium  compounds  in  alcoholic,  or 
aqueous  solution,  furnish  ethylamine.  This  amine  can 
be  attacked  in  its  turn  by  iodide  of  ethyl  and  yields 
diethylamine  and  oxide  of  tetrethylarnrnonium.  The 
knowledge  of  these  reactions  and  their  application  to 
other  iodides  are  the  basis  of  a  general  mode  for  the 
preparation  of  organic  bases  originated  by  Hoffmann. 
Iodide  of  ethyl,  unlike  the  chloride,  is  readily  decom- 
posed by  solutions  of  silver  nitrate,  giving  a  precipi- 
tate of  silver  iodide. 

C2H5I  +  AgN03  =  (C21I5)  N03  +  AgI. 

CYANIDE  OF  ETHYL,  OB  CYANHYDKIC  ETHER. 

C'a-tijj  ' 


This  ether  is  obtained  on  distilling  in  an  oil-bath 
1  part  of  potassium  cyanide,  with  1-5  part  of  an  alkaline 
sulpho-viuate.  To  the  product,  redistilled  in  a  bath  of 
salt-water,  nitric  acid  is  slowly  added  in  excess  ;  it  is 
then  subjected  to  another  distillation.  Finally,  it  is 
dried  over  calcium  chloride,  and  that  which  passes  over 
from  195°  to  200°  is  collected  on  redistillation. 

Cyanide  of  ethyl  is  a  colorless  liquid  of  an  alliaceous 
odor,  boiling  at  97?. 

Cyanide  of  ethyl  is  decomposed  by  potassium  hy- 
drate; ammonia  is  produced,  and  the  acid  obtained 
corresponds  with  a  higher  homologous  alcohol. 


78  ORGANIC     CHEMISTRY. 

CN(C,H5)  +  2H20  =  NH3  +  C3H602. 

Propionic  acid. 

M.  Meyer  observed  some  years  ago,  that  if  cyanide 
of  silver  is  treated  with  iodide  of  ethyl,  a  liquid  is 
formed,  boiling  at  82°,  of  an  odor  which  is  not  that  of 
ordinary  cyanhydric  ether.  Gautier  has  shown  that  this 
is  an  isomeric  body,  arid  that  there  are  two  isomeric 
series  of  cyanhydric  ethers.  Hoffmann  has  given  a  dis- 
tinctive character  to  these  bodies:  under  the  influence 
of  the  alkalies  they  produce  a  fixed  substance,  but 
this  is  formic  acid  and  not  ammonia,  and  a  volatile 
substance  which  is  a  compound  ammonia. 

H    ) 
CN(C2II5)  +  211,0=  CH,02  +  Coll5  V  N. 

~^     "H  \ 
•"•  / 

Formic  acid.       Ethylamine. 

OKGANO-METALLIC  COMPOUNDS. 

Iodide  of  ethyl  attacks  the  metals  and  furnishes  a 
class  of  bodies  called  organo-metallic  radicles.  None 
of  these  bodies  are  found  in  nature.  They  are  formed 
from  the  iodohydric  ethers  by  the  substitution  of  a 
metal  for  the  iodine; 

Zn  +  2(C2H5I)  —  (C2H5),Zn  +  ZnI2, 
2Sn  +  2(C2H5I)  =  (C2H5),Sn  +  SnI2. 

Practically  these  metallic  radicles  are  obtained  by 
various  reactions: 


ORGANO-METALLIC  COMPOUNDS.  79 

1.  By  the  action  of  the  metal  upon  the  iodide,  for 
example; 

2C2H5I  +  Ziio=(C.Ji3)2Zn  +  Znl,. 

In  certain  cases,  with  tin  for  instance,  the  reaction  is 
not  as  distinct,  and  there  is  formed  in  addition  to  stan- 
nethyl iodide,  stannethyl  iodides  variously  condensed. 

2d.  The  metal  is  treated  with  another  radicle;  thus 
sodium-ethyl  is  prepared  by  the  action  of  sodium 
upon  zinc  ethyl, 

(C2H5)2Zn  +  ]XTas= Zn  +  2C2H5Na. 

3d.  On  decomposing  a  metalloid  compound  radicle 
with  a  metallic  chloride, 

3ZnCla+2(C2H5)3P=3(CaHg)Zn  +  2PCls. 

4th.  Stannethyl  is  obtained  by  plunging  a  plate 
of  zinc  into  a  soluble  salt  of  this  radicle:  the  radicle 
is  precipitated  in  the  form  of  an  oily  liquid. 

Cacodyl,  As(CH3)2  was  the  first  discovered  of  this  class 
of  bodies.  It  was  obtained  by  Bunsen  on  distilling 
arsenous  acid  with  potassium  acetate.  The  organic 
radicles  combine  with  metalloids  with  more  or  less 
energy  ;  zinc-ethyl  and  cacodyl  take  fire  in  the  air ; 
they  also  decompose  water.  The  products  of  oxida- 
tion vary  with  the  nature  of  the  compounds  employed; 
zinc-ethyl  furnishes  the  body,  C,IIr)ZnO,  zinc-ethyl- 
ate,  which,  in  contact  with  water,  produces  alcohol  and 
oxide  of  zinc.  The  metals  which  are  less  readily  oxy- 


80  ORGANIC     CHEMISTRY. 

dized,  such  as  tin,  lead  and  mercury,  give  oxides- 
which  play  the  parts  of  bases,  and  these  latter  com- 
port themselves  like  the  oxides  of  the  metals  they  con- 
tain. Finally,  the  radicles  formed  by  the  elements, 
phosphorus,  arsenic,  and  antimony,  give,  with  oxy- 
gen, compounds  which  generally  have  the  character  of 
acids. 

Some  of  the  organic  derivatives  containing  phos- 
phorus are  very  complex.  For  instance,  J.  Auauoif 
(00-' 75-493)  has  obtained  a  body  he  denominates, 
methyldiethylpliosphoniumpkenyloxidekydrate! 

To  prepare  zinc-ethyl,  \ve  introduce  into  a  flask 
connected  with  a  condenser  inclined  in  such  a  manner 
that  the  vapors  find  their  way  back  into  the  flask,  100 
grains  iodide  of  ethyl,  75  grams  of  zinc,  and  6  to  7 
grams  of  an  alloy  of  zinc  and  sodium,  and  heat  in 
the  water  bath  until  the  zinc  is  dissolved ;  then  the 
condenser  is  inclined  as  usual,  and  the  distilling  is 
effected  over  a  direct  fire,  collecting  the  liquid  pro- 
duct in  a  flask  filled  with  dry  carbon  dioxide. 
Finally  it  is  again  distilled  in  this  gas,  and  that  col- 
lected which  passes  over  from  116°  to  120°.  All  the 
vessels  and  all  the  substances  should  be  absolutely 
dry,  and  it  should  always  be  collected  and  distilled  in 
vac'iio,  or  in  carbon  dioxide.  It  is  a  colorless  liquid, 
whose  density  is  1.182,  boiling  at  118°,  inflammable 
on  exposure  to  the  air. 

"With  sodium  this  body  furnishes  sodium-ethyl,  and 
with  chloride  of  phosphorus  or  arsenic,  it  furnishes 
triethyl  phosphine,  PvCoH5)3,  and  triethyl  arsine, 


ETHERS.  81 

Mercury-methyl,  treated  with  iodine,  furnishes  a 
hydroearbide  which  has  the  formula  of  methyl,  CH8. 

Professors  Crafts  and  Friedel  (72-[4]19-334)  have 
prepared  a  large  number  of  compounds  of  silicon  with 
compound  radicles,  from  which  they  have  deduced 
valuable  theoretical  considerations. 

MISCELLANEOUS  ETHERS. 

Formic,  butyric,  valerianic  ether,  and  other  ethers 
of  the  fatty  series  are  prepared  in  the  same  manner  as 
acetic  ether,  and  have  the  general  properties  of  this 
ether.  The  odor  of  these  ethers  is  agreeable.  Bu- 
tyric ether  has  the  odor  of  pine-apple,  and  valerianic 
ether  that  of  pears  ;  cenanthylic  ether  has  the  aroma 
of  wine,  etc.  They  are  used  in  the  manufacture  of 
syrups,  flavoring  extracts,  and  for  imparting  an  odor 
to  liquors. 

If  the  difference  between  the  points  of  ebullition  of 
these  ethers  is  examined  it  will  be  seen  that  the 
addition  of  the  elements  CIL  causes  an  elevation  of 
about  20°  in  the  point  of  ebullition.  Kopp  has 
shown  that  this  fact  is  a  general  one  and  applies 
to  the  alcohols,  and  acids  of  the  same  series,  and  to 
the  homologous  bodies  in  general. 

Point  of  ebullition.  Difference. 
Formic    ether,     .-        -       55°  1QO 

Acetic         "  -          74°  J^0 

Propionic   "     -  95°  jJ0 

Butyric       "  -       119°  7T0 

Valerianic "     -         -          133° 


82  ORGANIC    CHEMISTRY. 

The  boiling  point  of  one  of  these  bodies  may  accord- 
ingly be  predicted,  if  that  of  one  of  its  homologous 
substances  is  known.  There  is  a,  certain  close  relation 
between  the  point  of  ebullition  of  an  ether  and  that 
of  the  acid  whose  radicle  it  contains: 

Point  of  ebullition.     Difference. 

Formic  acid,  105°  ) 

"       ether,  -       55°  [                     50° 

Acetic  acid  -    118°) 

"      ether,  74°  )                     44° 

Propionic  acid,  -      1 40°  / 

"       ether,     -  95°  J                      45° 

Butyric  acid,          -  .-         163°  ) 

"       ether,     -  -    119°  \                     44° 

The  solubility  in  water  of  the  ether  formed  by 
homologous  acids  varies  with  the  molecular  weight  ; 
thus  formic  ether  is  quite  soluble,  acetic  ether  is  less 
soluble,  butyric  ether  is  but  slightly  so,  and  valerianic 
ether,  which  follows  it,  is  nearly  insoluble. 

MERCAPTANS    AND    THEIR    ETHERS. 

On  substituting  sulphur,  selenium,  or  tellurium  for 
oxygen  in  the  alcohols  of  different  atomicity,  sulphur, 
selenium,  or  tellurium  alcohols  are  obtained,  which 
are  designated  as  mercaptaiis,  selenium  mercaptaiis, 
and  tellurium  mercaptans. 

Ethers  proper  correspond  to  these  as  to  ordinary  al- 
cohols. These  ethers  are  derived  either  by  the  substi- 


ETHEES.  83 

tution  of  an  alcohol  radicle  for  the  typical  hydrogen, 
as  happens  with  monatomic  mercaptans,  or  by  the 
elimination  of  H2S,  as  is  the  case  with  biatomic  mer- 
captans. 

One  only  of  each  of  these  two  classes  will  be  alluded 
to  here. 

Ethyl  sulphide,  or  hydrosulphu-  )  n  TJ   Q     C2H5  )  c 
ric  ether,  f  °4lil°b  =C2H5  f  b" 

Ethyl  mercaptan,  C4H6S=°2^5  [  S. 

To  prepare  the  sulphide  a  current  of  ethyl  chloride, 
is  passed  into  an  alcoholic  solution  of  potassium 
sulphide. 

The  mercaptan  is  prepared  by  the  action  of  potass- 
ium hydro-sulphide  on  ethyl  sulphide. 

In  either  case  potassium  chloride  is  formed. 


K.S  +2C2H5C1=C4H10 

KHS  +  C2H5C1=C2H6  S  +  KC1. 

These  bodies  are  afterwards  separated  by  distillation. 
Like  all  the  sulphur  derivatives  of  alcohol,  they  have  a 
nauseous  odor.  The  sulphide  boils  at  91°  the  mer- 
captan at  36°. 

MIXED    ETHERS 

containing  two  different  radicles,  are  obtained  by  act- 


84  ORGANIC    CHEMISTRY. 

ing,  for  instance,  with  ethyl  iodide  upon  potassium 
methylate,  thus  : 


ethyl  iodide,    potassium     potassium    methyl-ethyl 
methylate.          iodide.  ether. 


or  by  acting  on  hydric  methyl  sulphate      rr3     SO4 

with  ethyl  alcohol.     The  following  is  a  list  of  some  of 
the  more  important  mixed  ethers  of  the  monatomic 

series; 

TABLE    OF    MIXED  ETHEES.  BOILING    POINT. 

Methyl-ethyl  ether  03II8O=  2  S3  [  O       '  + 11° 

25; 

Methyl-amyl  ether  C6H14O  =£  ^  |  O  92° 

Ethyl-butyl  ether  C6II14()  =  22g5  I  O  80° 

Ethyl-amyl  ether    C7H16O  =  ^2gB  I  O  ]  12° 

Ethyl-hexyl  ether  C81I1SO  =  ^'g5  I  O  132°. 


ALDEHYDS.  85 


ALDEHYDS, 

The  following  are  the  principal  aldehyds,  arranged 
in  series: 

CnH2nO. 

Formic  aldehyd      -  -     C  H2  O 

Ethylic  aldehyd  C2  H4  O 

Propylic  aldehyd    -         -  -    C3H6O 

Butylic  aldehyd   -  C4H80 

Valeric  aldehyd  -         C5  H10O 

(Enanthylic  aldehyd  -       C7  H14O 

Caprylic  aldehyd    -        -  -     C8  H16O 

Caproic  aldehyd  CjoH.^O 

Rutic  aldehyd  CnH^O 

Ethalic  aldehyd  Ci^O 


Ally  lie  aldehyd  (acroleiri)     -      C3  H4O 

CnH2n4O. 
Campholic  aldehyd   (camphor)  C10H160 


86  ORGANIC    CHEMISTRY. 


Benzole  aldehyd  (oil  of  bitter  almonds)  C7  H6  O 
Toluic  aldehyd  C8  H8  O 

Cuminic  aldehyd  -  C10Hi.,O 

Sycocerylic  aldehyd  C^H^O 


Cinnamic  aldehyd  (oil  of  cinnamon)     -     C9H8O. 

Aldehyds  may  be  regarded  as  bodies  built  upon  the 
type  of  one  or  more  molecules  of  hydrogen,  in  which 
one  half  the  hydrogen  atoms  are  replaced  by  one  or 
more  molecules  of  an  oxidized  carbohydride. 

The  formation  of  aldehyd,  (alcohol  <^fo/c?rogenated), 
may  be  illustrated  by  the  following  equation  : 

C2H60—  H2  —  C2H4O 


Ethyl  alcohol.  Ethyl  aldehyd. 

Aldehyds  are  obtained  by  the  oxydation  of  alcohols, 
but  they  are  only  the  first  products  of  oxydation.  They 
are  capable  of  combining  with  an  additional  molecule  of 
oxygen,  forming  acids;  hence  the  aldehyds  are  inter- 
mediate between  alcohols  and  acids. 

ORDINARY    ALDEHYD. 

C2H4O=C2H3O 

II 

This  substance  is  formed  by  the  slow  oxydation  of 
alcohol. 


ALDEHYDS.  87 

Alcohol  is  treated  with  a  mixture  of  manganese 
binoxide,  or  of  potassium  bichromate,  and  sulphuric 
acid,  and  distilled,  care  being  taken  to  keep  the  re- 
ceiver well  cooled.  Besides  aldehyd,  acetyl,  acetic 
ether,  acetic  acid  and  water  are  formed.  The  product 
is  again  distilled,  care  being  taken  to  collect  only  that 
portion  which  passes  over  above  60°.  This  liquid  is 
mixed  with  ether,  and,  when  cool,  a  stream  of  dry 
ammonia  gas  is  caused  to  pass  through  the  solution. 
Crystals  of  ammonium  aldehyd  are  formed, 
CoH3(XH4)O,  which  are  decomposed  by  dilute  sul- 
phuric acid.  The  mixture  is  then  distilled. 

Aldehyd  is  a  colorless,  very  volatile  liquid.  It  is 
soluble  in  water,  alcohol  and  ether,  and  possesses  a 
strong,  somewhat  stifling  odor. 

The  salient  property  of  aldehyd  is  its  avidity  for 
oxygen.  If  a  few  drops  are  poured  into  water  the 
latter  becomes  acid;  it  is  therefore  a  valuable  reduc- 
ing agent. 

C  TT  O  ) 

If  aldehyd,  or  ammonium  aldehyd,      2xr3o    [    is 

poured  into  an  ammoniacal  solution  of  silver  nitrate, 
on  slightly  elevating  the  temperature,  metallic  silver  is 
deposited.  This  silver  adheres  to  the  sides  of  the  tube, 
and  covers  it  with  a  mirror-like  coating.  This  prop- 
erty is  the  basis  of  a  process  of  silvering  glass  globes 
and  other  hollow  articles  of  glass. 

Aldehyd  is  attacked  by  chlorine  and  bromine,  and 
furnishes,  by  substitution,  various  products,  of  which 

CHLORAL   C2IiCl3O,  is   the   most  important.     Hy. 


88  ORGANIC    CHEMISTRY. 

drate  of  chloral,  or  CoHCLjO  +  H./^hasbeen  prepared 
now  for  several  years  in  very  large  quantities,  for 
medicinal  purposes^  Its  name  is  derived  from  chlor- 
ine  alcohol. 

Absolute  alcohol  is  saturated,  first  cold,  then  hot, 
with  dry  chlorine.  The  liquid  obtained  is  mixed  witli 
its  volume  of  concentrated  sulphuric  acid.  Tiie 
supernatant  liquid  is  decanted,  and  distilled  in  an 
earthern  retort,  with  one-fourth  its  weight  of  sulphuric 
acid.  The  anhydrous  chloral  obtained  is  re-distilled 
twice  with  calcium  carbonate  and  7  to  8  per  cent,  of 
water.  The  hydrate  is  then  obtained  in  handsome 
crystals,  C.JIC130  +  H>O,  soluble  in  water.  It  has 
been  known  for  sometime  that  this  body  is  decom- 
posed in  presence  of  alkalies  or  alkaline  carbonates, 
into  chloroform  and  formic  acid, 

C2HC13O  +  H2O  +  KIIO = ECHO,  +  CHC13  +  H2O. 

Potassium     Chloroform, 
formiate. 

The  question  appeared  pertinent  whether  a  similar 
transformation  would  be  effected  in  the  human  body, 
under  the  action  of  the  alkaline  fluids  there  present, 
notably  those  of  the  blood,  and  thus  develop  chloro- 
form. 

Liebreicli  was  the  first  to  administer  chloral,  and  he 
at  once  obtained  the  anesthetic  effects  of  chloroform. 
His  experiments  were  repeated  in  different  countries, 
and  hydrate  of  chloral  soon  came  into  general  use  as 
a  hyponotic. 


ALDEHYDS.  89 

Chloral  hydrate  for  medical  use  must  be  crystalline 
and  possess  the  following  properties:  it  should  be  col- 
orless, transparent,  and  have  an  aromatic  odor,  a  caus- 
tic taste,  readily  soluble  in  water  without  furnishing 
drops  of  oil,  also  soluble  in  alcohol,  ether,  naphtha, 
benzol,  and  carbon  bisulphide;  it  should  fuse  at  56°  to 
58°,  solidify  at  about  15°,  boil  and  volatilize  completely 
at  95°.  With  caustic  potassa  it  should  furnish  chloro- 
form, and  with  sulphuric  acid,  chloral,  without  becom- 
ing brown.  Its  aqueous  solution  should  be  neutral 
and  not  produce  any  turbidity  with  silver  nitrate  and 
nitric  acid.  Exposed  to  the  air  it  should  not  become 
moist.  Accordingto  recent  investigations  by  Liebreich, 
(60-69-673)  chloral  produces  the  opposite  physiolog- 
ical effects  of  strychnine,  heuce,  these  bodies  may 
be  used  as  antidotes  one  for  the  other. 

The  remaining  aldehyds  are  not  sufficiently  im- 
portant for  a  work  of  this  scope.  Camphor  has  al- 
ready been  considered  in  connection  with  turpentine. 


90  ORGANIC     CHEMISTRY. 


ORGANIC  ACIDS. 

ACIDS   CONTAINING  TWO   ATOMS  OF  OXYGEN. 
FATTY    ACID   SERIES. 

CnH2nO,. 

Formic        acid,     -  C  H3  O2 

Acetic            "  C2  H4  O2 

Prop  ionic       "     -                  -  C3H6O2 

Butyric           "  C4 II8  O* 

Valeric            «  C5  H10O, 

Caproic                                      -  C6H12O* 

(Emmthylic    u  C7H14Oa 

Caprylic  C8  H16O2 

Pelargonic      "     -                  -  C9H18O2 

Capric  C10II:oO, 

Laurie            "     -                 -  C,,!!^ 

Coccinic         "  Ci3II26O2 

Myristic          "      -  CuII^A 

Palmitic         "  C16If3.,O2 

Margaric        "     -                   -  Cnl^O, 

Stearic           "  CJ8II36O2 

Arachidic       "                  .         -  C^II^Oa 

Cerotic           "     -  C^H^O, 

Melissic         "      -        -        -.  Cs^IeA. 


ORGANIC  ACIDS.                                   91 

CnH2n_A. 

Acrylic      acid     -  -       C3H4O2 

Crotonic        "  C4  H6  O2 

Angelic         "     -  -      C5H8O2 

Pyroterebic  "  C6HioO2 

Campholic     "     -  -       CioH18O2 

Moringie       u  -  CjsELgOa 

Pliysetoleic  "     -  -       C16H3oO2 

Oleic             "  CujHsA 

Doeglic         "      -  -       Q^HaeQs 
Erucic           " 


Sorbic    acid  C6  H8  O2 

Camphic  *'  C10H16O2- 

AROMATIC   ACID    SERIES. 


Benzoic  acid  C7  H6  O2 

Toluic       "  -       C8H8O2 

Xylic        u  C9H1002 

Cumic       "  -.    C10H12O2 

Alpha-cymic  acid  -                 CnH14O2. 


Cinnamic  acid  C9  H8  O2 

Pinic  "      -          -         - 


ORGANIC     CHEMISTRY. 
ACIDS   CONTAINING  THKEE   ATOMS  OF  OXYGEN. 

CnH2n03. 

Carbonic  acid  C  H2O3 

Glycolic  "  -                -    C2H4O3 

Lactic  "  C3  H6  O^ 

Oxybutyric  "  -                       C4H8O3 

Oxyvaleric  "  C5  H10O3 

Leucic  "     -  -      C6H12O3 

(Enanihic  "  CuHj. 


Pyrnvic        acid  C3  H4  O3 

Scammonic     "  Cjgll^Oj 

Ricinoleic       "     -  -       CjgH^Os. 


Guaiacic       acid  C6  H8  O3 

Lichenstearic  "      -  -     C9HUO3 


Pyromeconic  acid       -  C5  H4  O 


Salicylic     acid     -  C7H6O3 

Anisic          "  -     C8I1,O3 

Phloretic      "  C9H:0O,, 

Oxycuminic  '•  -     CIOH12O3 

Thymotic     "     -  CUH14O3. 


ORGANIC    ACIDS  93- 

^n-t*-2n— 10^3. 

Coumaric  acid      -  -       C9  H8  O3. 

ACIDS   CONTAINING    FOUR    ATOMS   OF   OXYGEN. 

CnH2nO4. 
Gljceric  acid  C3H6O4.. 


Oxalic  acid  C2  H2  O^ 

Malonic  "  C3H4O4 

Succinic  "  C4  H6  O4 

Pyrotartaric  "  C5H8O4 

Adipic  C6  H10O4 

Pimelic  "  C7  H12O4 

Suberic  "  C8H14O4 

Anchoic  "  C9  H16O4 

Sphif  "  C  TT  O 

**j\^  kj±\j  vy  jQi-j-i^vy^i 

Koccellic  "  Ci7H<BO4. 


Fumaric  acid  C4  H4  O4 

Citraconic  "  C5  H6  O4 

Terebic  "  C7  H10O4 

Camphoric  "  Ci0H16O4 

Lithofellic  "  C^HsgO,.. 


94  ORGANIC    CHEMISTRY. 


Mellitic  acid  C4H2O4 

Terechrysic       "  C6H6O4. 


Teratric  acid  C9Hi0O4. 


Phtalic  acid  C8  H6  O4 

Insolinic  C9H8O4 

Choloidic  "  CHO. 


Oxynaphthalic  acid  C10H6  O4 

Piperic  "  C12H10O4. 

ACIDS   CONTAINING     5,     6,     7     AND     8     ATOMS   OF   OX  YUEN. 


Tartronic  acid  C3H4O.-( 

Malic  «  C4H6O3- 


Mesoxalic  acid  C3H2O5. 


ORGANIC    ACIDS.  95 

Cholesteric  acid  C8H10O3. 


Croconic  acid  Cg  H2  O5 

Comenic  "  C6H4O5 

Gallic  "  C7H6O5 

Cholalic  "  CsJIaA. 

CnH2n_2O6. 

Tartaric   acid  C4H6  O6 

Quinic       "  C7H12O6. 


Carballylic  acid  C6H8O6. 

CnH^^Og. 

Aconitic  acid  C6H6O6. 

CnH2n_1oO6. 

Chelidonic  acid  C7H4  O6 

^n-H-an—  10^7- 

Meconic  acid  C7H4  OT 

Citric  acid  C6HS  O7 

Mucic  "  C6H10OS. 

Org  anio  acids  are  bodies  built  upon  the  type  of  one 
or  more  molecules  of  water,  Jiaving  one  half  the  hy- 
drogen replaced  by  an  organic  compound  radicle  con- 


96  OEGANIC     CHEMISTKY. 

taining  oxygen.  There  are  some  acids  whose  compo- 
sition is  not  definitely  fixed.  We  shall  first  examine 
the  monatomtc  acids,  and  study  the  other  series  in  the 
order  of  their  atomicity. 

The  organic  acids  possess  the  general  properties  of 
the  mineral  acids.  Many  among  them,  like  acetic  acid, 
have  a  very  decided  action  upon  litmus.  Generally, 
they  are  solid  and  crystallizable;  however,.formic,  pro- 
pionic,  butyric  acids,  etc.,  are  liquid.  Acids  whose 
molecules  are  comparatively  simple,  are  ordinarily  sol- 
uble in  water — the  others  are  little,  or  not  at  all,  soluble 
in  this  solvent.  The  monobasic  acids  are  volatile,  at 
least  where  their  molecules  are  not  very  complex.  The 
polybasic  acids  are  decomposed  by  heat.  Their  salts 
are  ordinarily  crystallizable. 

METHODS   OF   PREPARATION. 

I.  The  acids  of  the  so-called  fatty  series  are  ob- 
tained by  the  oxidation  of  the  corresponding  alcohol, 
or  aldehyd,  which  latter  is  the  first  product  of  oxida- 
tion of  the  respective  alcohol. 

cyri^o+o  =c,ir4o+n2o. 

Acetic  aldehyd. 

C2H40+0=C2H40,. 

Acetic  acid. 

II.  These  acids  are  also  produced  by  the  action  of 
alkalies  upon  the  cyanide  of  the  radicle  appertaining 
+o  the  homologous  inferior  alcohol. 


ORGANIC    ACIDS.  97 

(CH3)CN  +  KHO  +  H2O=NH3  +  KC2H3O2. 


Methyl  cyanide.  Potassium  acetate. 

III.  Acids  are  likewise  formed  by  the  union  of  the 
elements  of  carbon  monoxide  and  carbon  dioxide  with 
hydrogen  carbides  and  water.  The  remarkable  syn- 
thesis of  formic  acid  by  Berthelot  is,  according  to  this 
method : 

CO  +  H20=CHA- 

Pelouze  has  shown  that  heat,  carefully  applied  to 
polyatomic  acids,  causes  them  to  part  with  a  certain 
number  of  molecules  of  water,  of  carbon  dioxide,  or  of 
both,  and  furnishes  acids  more  simple  and  of  a  lower 
equivalence,  which  he  designates  by  the  name  oi'pyro- 
acids. 

2C4H6O6 =C,H8O4  +  2H2O  +  3CO2 . 

Tartaric  acid.  Pyro-tartaric  acid. 

Of  all  the  series  of  acids,  the  most  numerous  and  the 
most  important  are  those  of  the  so-called  fatty  series- 
We  shall  presently  indicate  the  methods  by  which  they 
are  obtained. 

Their  boiling  point  increases  from  15°  to  20°  with 
each  addition  of  CI12  to  their  molecule.  Certain  of 
their  salts,  those  of  calcium,  for  instance,  are  decom- 
posed by  heat,  furnishing  compounds  called  acetones. 


98  ORGANIC     CHEMISTRY. 

Ca(C2H302)2=(  .'aCO,  +  C,II60. 

Calcium  acetate.  Ordinary  acetone. 

FORMIC    ACID. 

CH.,0.,=CH  O  )  r 

ii  r 

Red  ants  made  to  pass  over  moistened  blue  litmus 
paper  produce  red  stains.  The  acid  secreted  by 
these  insects  was  first  obtained  by  Gehlen,  and  lias  re- 
ceived the  name  of  formic  acid. 

I.  Berthelot    lias  obtained  it    from    carbon    mon- 
oxide by  synthesis. 

II.  It  is  prepared  by   distilling   a  mixture  of  10 
parts  of  starch,  30  parts  of  sulphuric  acid,  20  parts  of 
water,  and  37  parts  of  manganese  binoxide  in  a  large 
retort  connected  with  a  condenser. 

The  mass  swells  considerably,  and  at  first  must  be 
heated  but  gently.  The  formic  acid  is  distilled  over 
and  saturated  with  lead  carbonate.  The  fbrmiate  of 
lead  is  caused  to  crystallize  in  boiling  water,  then 
placed  in  a  retort  and  decomposed  by  a  current  of  hy- 
drogen sulphide  and  thereupon  heated;  the  formic  acid 
is  then  distilled  off. 

III.  One  kilo  of  glycerine,  150  to  200  grams  of  water 
and  1  kilo,  of  oxalic  acid  are  introduced  into  a  retort 
and  heated  for  15  hours  at  a  temperature  of  about  100". 
The  oxalic  acid  is  decomposed,  but  only  carbon  di- 
oxide is  disengaged.     "Water  is  added  from  time  to 


ACETIC    ACID.  99 

time,  and  the  mixture  then  distilled  until  8  litres  have 
passed  over.  The  glycerine  remains  unchanged  in  the 
retort,  and  can  again  he  used. 

Formic  acid  is  a  colorless  liquid,  of  a  very  acid  re- 
action, a  pungent  odor  and  crystallizing  at  about  0° 
and  boiling  at  104°. 

It  reduces  oxide  of  mercury,  furnishing  mercury,  as 
a  brown  powder,  also  carbon  dioxide  and  water.  Its 
salts  are  usually  soluble,  though  that  of  lead  is  very 
little  soluble  in  cold  water,  but  quite  soluble  in  borl- 
ing  water. 

On  heating  with  sulphuric  acid,  carbon  monoxide 
and  water  are  formed. 

EXPERIMENT. — Introduce  into  a  test-tube  a  small 
quantity  of  formic  acid  or  a  formiate.  Add  sulphuric 
acid  and  heat;  a  regular  liberation  of  a  gas  takes  place, 
which  may  be  ignited,  producing  a  blue  flame. 

=  CO+H,0. 

ACETIC  ACID. 

O. 


C,H4O2=C2H3O 


H 

Sp.  Gr.  1.08.     Density  of  vapor  30. 

Glacial  acetic  acid  melts  at  17°;  boils  at  118°. 

This  is  the  acid  of  vinegar,  and  of  which  it  forms 
the  essential  part.  It  is  found  in  the  juices  of  many 
plants  and  in  certain  fluids  of  the  body.  It  is  formed 
by  synthesis  from  methyl,  sodium,  or  potassium  for- 


100  ORGANIC    CHEMISTRY. 

miate,  and  by  the  oxidation  of  acetylene;  also  by  the 
action  of  nitric  acid  upon  fatty  substances,  and  by  the 
reaction  of  potassa  upon  tartaric,  malic  and  citric  acids. 
It  is  further  produced: 

I.  By  the  oxidation  of  alcohol  in  the  following  way: 
"Wine  in  vats,  or  casks,  is  placed  in  a  cellar  main- 
tained at  a  temperature  of  about  30°;  every  sixth  or 
eighth  day  several  litres  of  vinegar  are  withdrawn  and 
replaced  by  an  equal  quantity  of  wine. 

Pasteur  has  established  that  the  oxydation  of  alco- 
hol is  produced  by  a  minute  plant,  the  Mycoderrna 
aceti.  In  fact,  acetification  commences  only  when 
this  plant  has  been  formed  in  the  liquid.  If 
its  development  is  interrupted  the  oxydation  stops;  it 
renders  the  service  of  taking  oxygen  from  the  air  and 
transferring  it  to  the  alcohol. 

This  process  is  very  slow.  It  may  be  rendered  more 
rapid  by  pouring  dilute  alcohol  on  beach-wood  shav- 
ings placed  in  barrels.  The  air  penetrates  through 
openings  made  in  the  lower  portion.  The  alcohol, 
after  having  been  passed  over  the  shavings  four  times, 
will  be  found  sufficiently  acetified,  if  the  temperature  is 
maintained  at  about  25°. 

II.  DISTILLATION  OF   WOOD.     PYROLIGNEOUS    ACID. 
Wood  is  distilled  in  retorts  ,  yielding  vapors  and  gases. 
The  former  are  condensed  by  causing  them   to  pass 
through  a  condenser  ;  the  erases  are  conducted  under 

O  O 

the  retorts,  where  they  are  burned,  and  the  heat  util- 
ized in  the  distillation  of  the  wood. 

The  condensed  liquids  are  water,  acetic  acid,  wood 


ACETIC    ACID.  101 

spirit  and  tar ;  the  greater  portion  of  the  tar  is  me- 
chanically removed  and  the  remaining  liquid  distilled 
in  a  water  bath.  The  wood  spirit,  which  boils  at  63° 
passes  into  the  receiver.  The  water  and  acetic  acid 
remaining  in  the  retort  are  saturated  with  sodium 
carbonate,  the  product  is  evaporated  to  dryness  and 
heated  from  250°  to  350°  ;  this  temperature,  while  not 
effecting  the  decomposition  of  the  sodium  acetate 
is  sufficient  to  carbonize  the  tarry  substance  remaining 
in  solution.  The  mass  is  thereupon  dissolved  in  water, 
filtered,  and  the  acetate  allowed  to  crystallize.  If  it  is 
desired  to  obtain  the  acetic  acid  uncombined,  the  solu- 
tion of  the  salt  is  distilled  with  a  slight  excess  of  sul- 
phuric acid. 

The  acetic  acid  which  distils  over  contains  a  large 
amount  of  water.  Normal,  or  anhydrous  acid  may  be 
obtained  from  it  by  saturating  half  of  the  liquid  with 
sodium  carbonate,  then  adding  the  remainder  to  this 
solution ;  acid  sodium  acetate  is  thereby  produced, 
•which  is  evaporated  to  dryness  and  distilled  with  sul- 
phuric acid.  This  liquid ,  cooled  with  ice,  gives  crystals 
of  normal  acetic  acid,  which  can  be  separated  on  de- 
canting the  liquid,  furnishing  the  so-called  glacial 
acetic  acid. 

Acetic  acid  is  liquid  above  17°;  below  that  it  crys- 
tallizes in  handsome  plates.  It  is  a  strong  acid,  has  a 
pronounced  odor,  and  is  very  caustic,  producing  blis- 
ters on  the  skin.  It  is  soluble  in  water,  alcohol  and 
ether  in  all  proportions.  It  dissolves  resin  and  cam- 
phor, also  fibrin  and  coagulated  albumen.  On  uniting 


102  ORGANIC    CHEMISTRY. 

with  water  it  contracts  in  volume.  A  red  heat  de- 
stroys it,  many  products  being  formed;  methane, 
acetylene,  acetone,  benzol,  naphthalin,  etc.,  also  car- 
bon, which  remains  in  the  retort. 

If  a  flask  containing  chlorine  gas  and  a  small  quan- 
tity of  acetic  acid,  is  exposed  to  the  sunlight,  triehlor- 

acetic     acid     is     formed,         J  Vr  r  O.     This  experi- 

ment of  Dumas  served  as  a  basis  for  the  theory  of 
substitution.  Le  Blanc  has  also  obtained  monochlor- 

acetic  acid  CoHoCIO  )  ,^     rpi         -,,    • 

TT  J-  O.     These  chlorine  products  are 

reduced  to  the  state  of  acetic  acid  by  reducing  agents, 
such  as  sodium  amalgam  in  presence  of  water, 

(H2)8+CaHCl302=3HCl+C2H402. 

In  the  same  manner  as  acetic  acid,  heated  with  an 
excess  of  a  base,  furnishes  marsh  gas,  trichlor, 
acetic  acid  produces  trichlorinated  marsh  gas,  which 
is  chloroform, 


C2H4O2+BaO=BaC08 
C2HClA+BaO=BaCO3  +  CHC13. 

Perchloride  of  phosphorus,  in  the  hands  of  Gerhardt, 
has  become  the  means  of  an  important  discovery,  that 
of  acetic  anhydride  and  in  general  of  the  anhydrides 
of  the  monobasic  acids.  If  dry  sodium  acetate  (3 
parts)  is  mixed  with  the  perchloride,  or  better,  with  oxy- 


VINEGAR. 


103 


chloride  of  phosphorus,  (1  part),  and  then  distilled,  a 
chloride  is  obtained  called  acetjl  chloride, 

C.,H3OC1=C.JI,0  | 

"  Cl    p 

acetyl  being  the  radicle  of  acetic  acid.  This  chloride, 
subjected  to  the  action  of  an  excess  of  sodium  acetate, 
is  decomposed  and  furnishes  acetic  anhydride, 

C2H30  \  Q 


(also  called  acetate  of  acetyl)  or  acetic  oxide,  which 
boils  at  139°.  Water  destroys  it,  acetic  acid  being 
produced.  Chloride  of  acetyl  is  an  irritating  liquid, 
boiling  at  about  158°,  decomposable  by  water  into 
acetic  and  hydrochloric  acids. 

A  derivative  of  acetic  acid  of  considerable  theoretical 
importance  is  cyanacetic  acid  C3H3NO2=C2H3O 


a  crystalline  body  forming  salts  with  the  metals,  which 
have  been  studied  by  T.  Menies.  On  acting  with  sul- 
phuric acid  and  zinc  on  cyanacetic  acid,  the  author 
[82-67-69]  obtained  formic  and  acetic  acids  and  am- 
monia. 

VINEGAR.  This  name  is  given  to  the  mixture  which 
is  obtained  by  the  acetification  of  wine,  whiskey,  infu- 
sion of  malt,  etc.  Good  acetic  vinegar  is  of  an  agree- 
able taste  and  aroma.  Wood  vinegar  has  a  very 
strong  disagreeable  taste  and  odor.  It  is  frequently 


104  ORGANIC    CHEMISTRY. 

adulterated  with  sulphuric  acid.  An  addition  of 
of  its  weight  of  this  acid  is,  however,  not  considered 
fraudulent,  as  its  presence  is  regarded  necessary  to 
prevent  moulding. 

A  ready  method  of  detecting  mineral  acids,  pro- 
posed by  M.  "Witz  (77-75-268),  is  based  upon  the  use 
of  methyl-aniline,  which  undergoes  no  change  in  con- 
tact with  acetic  acid,  but  promptly  changes  to  a  green- 
ish-blue in  presence  of  the  least  trace  of  mineral  acid. 

Vinegar  and  concentrated  acetic  acid  are  employed 
in  medicine  as  stimulants. 

An  acetate,  or  acetic  acid,  can  be  recognized  by  heat- 
ing it  slightly  with  sulphuric  acid  and  alcohol  ;  a 
fragrant  odor,  characteristic  of  acetic  ether,  is  observed. 
Heated  with  sulphuric  acid  alone,  the  acetates  liberate  a 
vapor  which  has  the  odor  of  vinegar. 

The  following  reaction  permits  of  the  detection  of 
mere  traces  of  acetic  acid;  it  is  saturated  with  potas- 
sium carbonate  and  heated  with  arsenous  oxide  in  a 
test  tube;  fumes  and  a  nauseating  odor  are  given  off. 

The  author  finds  that  one  of  the  simplest  tests  for 
acetic  acid,  is  to  direct  a  fine,  yet  powerful  stream  of 
water  into  a  test-tube,  containing  a  few  drops  of  the 
liquid  to  be  tested.  The  very  fine,  white  efferves- 
cence resulting  is  entirely  characteristic  of  this  acid, 
none  of  the  other  ordinary  acids  producing  the  same 
effect. 

Alcohol  should  not  be  present,  as  it  causes  a  similar 
effervesence.  If  the  acetic  acid  is  combined  it  should 
be  set  free  with  a  strong  mineral,  acid.  By  this  test, 


ACETATES.'  105 

perhaps  moi^  physical  than  chemical,  acetic  acid,  di- 
luted with  1000  parts  of  water,  can  be  readily  recog- 
nized, and  with  practice,  one  part  in  1500. 

ACETATES. 

Acetic  acid  is  monobasic;  there  are,  however,  alka- 
line biacetates  and  some  basic  acetates  of  copper  and 
lead. 

POTASSIUM    ACETATE. 


This  salt,  distilled  with  its  weight  of  arsenous  oxide, 
furnishes  a  very  inflammable  liquid,  formerly  called  the 
"liquor  of  Cadet,"  and  iu  which  Bunsen  has  found  a 
radicle  spontaneously  inflammable,  cacodyl,  C4ri12As2. 

Potassium  acetate  forms,  as  well  as  sodium  acetate, 
an  acid  acetate  when  treated  with  acetic  acid.  It  is  a 
very  deliquescent  salt,  difficultly  crystallizable. 

AMMONIUM    ACETATE, 


Is  prepared  by  saturating  ammonium  carbon- 
ate with  acetic  acid.  Its  solution  constitutes  the 
spirit  of  Mindererus  ;  treated  with  phosphoric  oxide  it 
forms  cyanide  of  methyl.  There  is  also  an  acid  salt, 
2.C2H4O2.  In  compounds  of  this  character, 


106  ORGANIC     CHEMISTRY. 

acetic  acid  must  be  considered  as  acting  the  same  part 
as  the  water  of  crystallization  in  salts. 

SODIUM   ACETATE. 

XaC2H302+3II2(). 

This  is  used  in  preparing  marsh  gas  and  concentrated 
acetic  acid.  It  is  recommended  by  Tommase  (52-72- 
23),  as  a  solvent  for  plumbic  iodide,  of  which  two  grams 
are  readily  dissolved  in  0.5  c.  c.  of  a  strong  solution  of 
sodium  acetate. 

CALCIUM  ACP:TATE. 


This  salt,  subjected  to  distillation,  furnishes  a  liquid 
containing  a  large  proportion  of  acetone  C3IT6O- 

ALUMINUM    ACETATE. 

A1(C8H803)8. 

This  body  is  employed  at  present  by  dyers,  as  a  mor- 
dant. It  is  prepared  by  causing  aluminum  sulphate 
to  react  upon  lead  acetate.  Lead  sulphate,  which  is 
insoluble,  is  separated  on  filtering  the  liquid. 

FERRIC    ACETATE. 

This  salt  (pyrolignite)  has  been,  and  is  still, 
somewhat  employed  for  the  preservation  of  wood. 


ACETATES.  107 


COPPER    ACETATES. 


Normal  acetate  Cn^HgOa)?  is  called  verditer.  It 
forms  beautiful  green  crystals  (crystals  of  Venus),. 
which,  subjected  to  distillation,  furnish  acetic 
acid  mixed  with  acetone.  During  this  operation,  a 
white  sublimate  is  formed,  which  deposits  in  the  neck 
of  the  retort.  This  latter  is  cuprous  acetate,  and  is  car- 
ried over  into  the  receiver,  oxydizes,  and  changes  into 
cupric  acetate,  which  colors  the  distillate  blue.  There 
remains  in  the  retort,  after  this  decomposition,  very 
finely  divided  copper  which  takes  fire  when  slightly 
heated  in  the  air.  Solutions  of  this  acetate  reduce  the 
salts  of  the  oxide,  CuO,  and  serve  to  prepare  the  sub- 
oxide,  Cu2O. 

A  basic  acetate,  designated  by  the  name  of  verdigris, 
is  obtained  by  exposing  to  the  air  sheets  of  copper 
moistened  with  vinegar,  or  surrounded  by  the  marc  of 
grapes.     The  metal  becomes  covered  with  a  greenish 
incrustation  whose  formula  is, 

Cu(C2H3O.;>2,CuO+6H2O. 

LEAD     ACETATE. 

The  normal  acetate  Pb(C2H3O.2)o  is  prepared  by  treat- 
ing litharge  with  acetic  acid  in  slight  excess.  This  salt, 
known  by  the  name  of  sugar  of  lead,  crystallizes  in 
oblique  rhombic  prisms,  soluble  in  two  parts  of  water 
and  eight  parts  of  95  per  cent,  alcohol.  It  has  a  sweet 
taste,  and  is  very  poisonous.  It  is  employed  as  a  re- 


108  ORGANIC    CHEMISTRY. 

agent,  also  to  prepare  aluminum  acetate  and  lead  chro- 
mate. 

In  digesting  acetic  acid  with  an  excess  of  litharge,  it 
furnishes  a  hexabasic  acetate  of  lead.  If  ten  parts  of 
normal  acetate,  with  seven  parts  of  litharge  are  taken  and 
this  mixture  digested  with  30  parts  of  water,  there  are 
formed  minute  needles  of  a  tribasic  salt  Pb(C2H3O2)2, 
PbO2,  TI2O.  Finally  this  salt,  dissolved  in  normal  ace- 
tate, gives  a  sesquibasic  acetate,  which  is  deposited  in 
crystals,  2(Pb2C2HA),PbO,II2O. 

GOULARD'S  EXTRACT  is  a  solution  containing  a  mix- 
ture of  normal  and  of  sesquibasic  acetate  of  lead, 
which  is  prepared  by  boiling  30  parts  of  water,  f  parts 
of  litharge  and  6  parts  of  normal  acetate  of  lead. 

BUTYRIC  ACID. 

CJW-C'H'°}0. 

It  is  usually  prepared  as  follows:  a  mixture  of 
10  parts  of  sugar,  1  part  of  white  cheese,  10  parts  of  chalk, 
and  some  water,  is  maintained  at  a  temperature  of  30° 
to  35°.  First,  lactate  of  lime  is  formed,  which  causes 
the  mass  to  thicken,  then  that  salt  changes  into  butv- 

?  O  *• 

rate,  disengaging  hydrogen  and  carbon  dioxide.  When 
the  mixture  has  become  clear,  the  liquor  is  evaporated 
and  the  butyrate  separated  with  a  skimmer.  This 
salt  is  decomposed  by  concentrated  hydrochloric  acid 
which  separates  the  butyric  acid  in  the  form  of  an  oil, 
which  is  distilled  off.  It  boils  at  163°.  It  is  of  a 
fetid  odor,  and  soluble  in  water,  alcohol  and  ether. 


VALEKIC    ACID.  109 

VALERIANIC,  OR  VALERIC  ACID  C5H10O2  =     5    Yi  [  ®- 

It  can  be  obtained  by  oxydizing  amylic  alcohol  by 
a  mixture  of  potassium  bichromate  and  sulphuric  acidv 
or  by  distilling  valerian  root  with  water  acidulated 
with  sulphuric  acid.  The  best  method  is  to  boil  por- 
poise oil  with  water  and  lime.  The  oil  saponifies  and  the 
valerianate  of  calcium  alone  is  dissolved.  This  liquid 
is  concentrated  and  hydrochloric  acid  added  in  excess. 
The  valerianic  acid  separates  out  in  the  form  of  an  oil 
which  is  distilled,  and  that  portion  collected  which 
passes  over  at  175°. 

Pierre  and  Puchot  have  lately  devised  a  process  for 
preparing  valeric  acid  from  amyl  alcohol.  (3-[3]  5-40. ) 

BEXZOIC  ACID,  C7H6O2. 

Density,  61. 

Density  of  its  vapor  compared  with  air,  4.27. 

Melts  at  120°;  boils  at  250°. 

It  is  obtained  by  a  dry,  as  also  by  a  wet  process. 
To  prepare  it  by  the  former  method,  equal  weights  of 
sand  and  gum  benzoin  are  placed  in  an  earthen  ves- 
sel, the  mixture  covered  with  a  sheet  of  filter  paper, 
which  is  pasted  down  round  the  edge,  and  a  long  cone 
of  white  cardboard  placed  over  the  whole.  The 
earthen  vessel  is  then  heated  over  a  slow  fire  for  two 
hours,  and  when  cool  the  cone  is  removed.  The  ben- 
zoic  acid  is  found  to  have  condensed  on  the  interior 
of  the  cone  in  handsome  blades,  or  needles. 


110  ORGANIC    CHEMISTRY. 

It  is  obtained  in  the  wet  way,  by  pulverizing  gum 
benzoin,  mixing  it  with  half  its  weight  of  lime,  and 
boiling  for  half  an  hour  in  a  cast-iron  kettle,  with  six 
times  its  weight  of  water,  care  being  taken  to  agitate 
the  mixture.  It  is  thrown  upon  a  piece  of  linen  and 
the  residue  treated  twice  with  water.  The  liquids  are 
reduced  in  volume  to  two-thirds  that  of  the  water  used 
during  the  first  treatment,  then  saturated  with  hydro- 
chloric acid.  The  benzoic  acid  separates  out,  and  is 
recrystallized  from  a  solution  in  boiling  water. 

It  is  also  procured  from  the  urine  of  herbivorous 
animals.  This  secretion,  evaporated  to  a  small  bulk 
and  treated  with  hydrochloric  acid,  yields  a  deposit  of 
hippuric  acid,  which,  on  being  heated  with  dilute  sul- 
phuric acid,  is  transformed  into  benzoic  acid. 

Benzoic  acid  is  also  produced  on  a  large  scale  from 
naphthalin. 

Benzoic  acid  crystallizes  in  lustrous  blades,  or  need- 
les, is  little  soluble  in  cold  water,  quite  soluble  in  boiling 
water,  and  still  more  so  in  alcohol  and  ether.  On 
passing  its  vapors  through  a  tube  heated  to  redness,  it 
is  decomposed  into  benzol  and  carbon  dioxide, 
C7H6Oo  =  r(iII6+CO2.  Chlorine,  bromine  and  nitric 
acid  transform  it  into  substitution  products. 

Chlorbenzoic  acid,  C7H3C1O. 
Dinitrobenzoic  "    C71I4(K"O,),O2. 

Ammonium  benzoate  furnishes,  on  distillation,  ben- 

zonitrile  C7XII,A  =  (\U-F  +  2II-A 

The   alkaline   benzoates   heated   with   chloride,   or 


BENZOIC    ACID.  Ill 

oxychloride  of  phosphorus,  furnish  benzyl  chloride, 
which,  submitted  to  the  action  of  potassium  benzoate 
in  excess,  gives  benzoic  anhydride, 

3(KCTH5O2)+POC1S  -  3(C7H5OC1)  +  K3PO4. 

Chloride  of  benzyl. 

CfHgOCl  +  KQHA  =  C14H1003  +  KC1. 

Benzoic  anhydride. 

The   rational   formula   of    benzoic    anhydride    is, 

C7II50  )  o 
C7TI5O  f  L 

Calcium  benzoate  heated  to  a  high  temperature 
furnishes  henzone, 

Ca(C7IIA)2=  CaCO3+CO(C6H5>2. 

Calcium^benzoate.  Benzone. 

Benzoic  acid  is  monobasic,  and  the  benzoates  are 
generally  soluble.  Benzoic  acid  taken  into  the  stom- 
ach, is  transformed  into  hippuric  acid. 

Kolbe  and  von  Meyer  have  observed  that  benzoic 
acid  has  antiseptic  power,  though  less  than  salicylic 
acid,  (18-[2]12-133). 

CINNAMIO  ACID.  In  certain  balsams  there  exists  an 
acid  called  dnnamic  acid,  whose  formula  is  C9II8O.,. 
It  exists  in  the  balsams  of  Peru,  benzoin,  tolu  and  in 
liquid  storax.  It  fuses  at  129°  and  boils  at  290°.  It 


112  ORGANIC     CHEMISTRY. 

• 

lias  striking  features  of  resemblance  to  benzole  acid, 
and  is  produced  like  the  latter  by  the  oxydation  of  an 
aldehyd.  This  aldehyd  is  the  essence  of  cinnamon 
prepared  by  distilling  cinnamon  with  water. 

POLYATOMIC  ACIDS. 

OXALIC    ACID. 


Vyo-LJ-2V^4==       TT 
-ti2 

PREPARATION.  In  the  burdock  and  sorrel  is  found 
an  acid  salt,  commonly  called  salt  of  sorrel,  which  is 
a  mixture  of  binoxalate  and  quadroxalate  of  potas- 
sium. Sodium  oxalate  is  found  in  several  marine 
plants,  calcium  oxalate  in  the  roots  of  the  gentian 
and  rhubarb,  and  in  certain  lichens.  Salt  of  sorrel  is 
extracted  from  the  burdock  (Prunex\  in  Switzerland, 
and  in  the  Black  Forest  of  Germany,  by  expressing 
the  plant,  clarifying  the  expressed  liquid  by 
boiling  with  clay,  and  evaporating  ;  crystals  of  salt  of 
sorrel  are  deposited. 

The  oxalic  acid  may  be  obtained  free  by  decompos- 
ing a  solution  of  these  crystals  with  lead  acetate ; 
the  oxalate  of  lead  which  precipitates  is  treated  with  a 
suitable  quantity  of  sulphuric  acid  ;  the  lead  is  com- 
pletely precipitated  as  lead  sulphate  ;  this  is  filtered 
off,  and  the  liquid  evaporated  and  allowed  to  crys- 
tallize. 

At  present  this  acid  is  chiefly  prepared  by  the  action 
of  oxydizing  agents  upon  certain  organic  substances; 
the  substances  best  suited  for  this  purpose  are  those 


OXALIC     ACID.  113 

which  contain  oxygen  and  hydrogen  in  the  proportion 
to  form  water.  One  part  of  starch,  or  sugar,  is  boiled 
with  eight  parts  of  nitric  acid  diluted  with  ten 
parts  of  water,  until  nitrous  vapors  cease  to  be  disen- 
gaged, and  the  liquid  then  evaporated.  The  crys- 
tals of  oxalic  acid  which  separate  out  are  freed  from 
the  excess  of  nitric  acid,  by  being  several  times  re- 
crystallized  in  water.  It  is  also  obtained  on  a  large 
scale  by  the  action,  at  a  high  temperature,  of  potass- 
ium or  sodium  hydrate  on  saw  dust. 

Oxalic  acid  has  been  obtained  synthetically,  by 
Drechel,  on  passing  carbon  dioxide  over  sodium  heated 
to  320°. 


PROPERTIES.  —  Oxalic  acid  crystallizes  in  prisms, 
which  effloresce  in  the  air,  and  which  are  very  soluble 
in  water  and  alcohol. 

It  fumes  at  98°;  at  170°  to  180°  it  is  partially  sub- 
limed, but  the  greater  portion  is  decomposed  into  car- 
bon monoxide,  carbon  dioxide,  formic  acid  and  water. 

2(CaH2O4)=CO  +  2COa+ClI2Oa+H2O. 

Chlorine,  hypochlorous  acid,  fuming  nitric  acid  and 
hydrogen  peroxide,  convert  oxalic  acid  into  carbon 
dioxide. 

Sulphuric  acid  causes  it  to  split  up  into  carbon  mon- 


1  14  ORGANIC     CHEMISTRY. 

oxide  and  carbon  dioxide,  and  this  reaction  is  made  use 
of  in  preparing  the  former  gas. 

Oxalic  acid  is  bibasic. 

Normal  potassium  oxalate,  Kg— Oa—OjOj. 
Acid  potassium  oxalate,  KH=O2=C2Oa. 

USES. — Oxalic  acid  is  employed  in  removing  ink 
spots  from  cloth,  and  in  cleaning  copper.  It  owes  these 
properties  to  the  fact  that  it  forms  with  iron  and  copper 
soluble  salts,  hence  it  is  also  employed  in  calico-works 
for  removing  colors. 

Toxic  action  of  oxalic  acid.  On  account  of  the  use 
of  oxalic  acid  in  the  arts,  and  its  physical  resemblance 
to  certain  salts,  particularly  to  magnesium  sulphate, 
poisoning  with  it  has  often  occurred,  either  through 
design  or  imprudence. 

It  acts  powerfully  upon  the  system.  Tardieu  men- 
tions the  case  of  a  young  man,  sixteen  years  of  age, 
who  was  poisoned  by  two  grams  of  this  substance. 

The  symptoms  observed  are  similar  to  those  pro- 
'dnced  by  other  corrosive  agents;  great  prostration  fol- 
lowed by  unconsciousness  and  a  persistent  numbness 
in  the  lower  extremities.  The  blood  of  the  patient  be- 
comes abnormally  red. 

In  cases  of  poisoning,  the  acid  should  be  removed 
from  the  stomach  with  promptness,  and  milk  of  lime, 
or  magnesium,  or  ferric  hydrate  administered.  Lime 
is  to  be  preferred,  as  it  forms  a  salt  completely  insol- 
uble in  vegetable  acids. 


SUCCINIC    ACID.  115 

8UCCINIC  ACID. 

H.!i°2- 

This  acid  is  produced  by  the  oxydation  of  butyric 
-acid,  and  by  subjecting  amber,  succinum,  to  dry  distil- 
lation or  by  the  action  of  iodhydric  acid  on  malic  or 
tartaric  acids. 

Succinic  acid  crystallizes  in  rhomboidal  prisms  which 
melt  at  180°  and  boil  at  about  235°,  at  a  higher  tem- 
perature they  are  decomposed  into  water  and  succinic 
anhydride  C4H4O3.  It  is  soluble  in  5  times  its  weight 
of  cold  water,  soluble  in  ether  and  very  soluble  in  alco- 
hol. 

It  is  used  in  the  artificial  preparation  of  malic  and 
tartaric  acids.  Succinic  acid  has  been  found  in  the 
fluid  of  the  hydrocele  and  of  certain  hydatids. 

MALIC  ACID. 

C4H302 )  0 
H,H2  f  °3' 

This  acid,  discovered  by  Scheele  in  sour  apples,  is 
found  in  many  plants ;  in  the  berries  of  the  service- 
tree,  in  cherries,  raspberries,  gooseberries,  rhubarb,  to- 
bacco, etc.  Malic  acid  is  levogyrate,  deliquescent 
and  crystallizable;  it  is  soluble  in  alcohol  and  fuses  at 
about  100°. 

At  a  temperature  above  130°,  it  is  decomposed  into 


116  ORGANIC     CHEMISTRY. 

various  acids  and  especially  para/malic  acid,  C4H4O4r 
which  is  identical  with  the  acid  of  the  fumaria.  It 
is  bibasic  like  oxalic  acid,  but  triatomic  and  is  dis- 
tinguished from  this  acid  by  not  producing  a  turbid- 
ity with  calcium  compounds. 

TARTARIC    ACID. 

CJ1A 
H2,I12 

This  acid,  obtained  from  wine  tartar  by  Scheele,  in 
17YO,  occurs  free  and  combined  with  potassium  in 
many  vegetable  products ;  in  the  sorrel,  berries  of  the 
service-tree  and  tamarind,  in  the  gherkin,  potato, 
Jerusalem  artichoke,  etc.  The  grape  is  the  chief 
original  source  of  this  acid. 

One  method  of  preparing  tartaric  acid  is  to  purify 
crude  tartar  by  dissolving  and  clarifying  with  clay, 
which  throws  down  the  coloring  matters:  then  filter- 
ing and  adding  calcium  carbonate,  which  precipitates 
half  of  the  tartaric  acid  as  a  calcium  salt. 

2KHC4H4O6+CaCO3=CaC4H4O6+KAH4O6+CO2+H20 

Hydro-potassic          Calcium    Calcium  tartrate.     Potassium 
tartrate.  carbonate.  tartrate. 

The  solution  which  contains  the  potassium  tartrate, 
is  filtered  and  calcium  chloride  added  :  the  remainder 
of  the  tartaric  acid  is  thus  precipitated  as  a  tartrate 
and  added  to  the  preceding. 


TARTARIC     ACID.  117 

K2C4H4O6+CaCl2=CaC4H4O6  +  2  KC1. 

Potassium  tartrate  Calcium  tartrate. 

These  precipitates  are  washed  and  decomposed  with 
sulphuric  acid,  the  calcium  sulphate  is  filtered  off,  and 
the  liquid  evaporated  to  the  point  of  crystallization. 
This  acid  is  also  called  right  tartaric,  or  dextroracemic, 
as  it  turns  the  plane  of  polarization  to  the  right. 

Kistner  has  obtained  from  certain  tartrates  a  tartaric 
acid  which  is  optically  inactive.  This  acid,  called para- 
tartaric  or  racemic  acid,  is  somewhat  less  soluble  than 
dextrotartaric  acid,  while  the  reverse  is  the  case  with 
its  salts.  It  contains,  moreover,  one  molecule  of  water 
of  crystallization,  but  does  not  crystallize,  as  does  the 
dextrogyrate  acid,  in  hemihedral  crystals. 

Levogyrate  tartaric  acid  is  prepared  by  evaporating 
a  solution  of  racemate  of  cinchonia;  the  levogyrate 
tartrate  precipitates  while  the  dextrogyrate  remains  in 
solution;  or  a  solution  of  racemic  acid  is  allowed  to 
stand  with  a  small  quantity  of  calcium  phosphate,  and 
a  few  spores  of  the  Pencilium  glaucumj  fermenta- 
tion sets  in,  which  destroys  the  dextroracemic  acid. 

Dextrotartaric  acid  crystallizes  in  beautiful  oblique 
prisms  with  a  rhombic  base.  Cold  water  dissolves 
twice  its  weight  of  this  acid;  alcohol  dissolves  it  with 
equal  facility.  It  is  insoluble  in  ether. 

Tartaric  acid  melts  at  about  180°;  and  furnishes  dif- 
ferent pyrogenous  acids,  chiefly: 

Tartaric  anhydride,  or  Tartrelic  acid,  C4H4O5,  and 

Pyrotartaric  acid,  C5H8O4. 


118  ORGANIC    CHEMISTRY. 

Simpson  synthesized  pyrotartaric  acid  and  Lebedeflf 
has  recently  (60-75-100)  shown  that  this  acid  is  iden- 
tical with  that  obtained  by  heating  tartaric  acid. 

Tartaric  acid  does  not  precipitate  calcium  salts.  It 
produces  a  turbidity  with  lime  water,  but  an  excess  of 
acid  dissolves  it;  by  these  reactions  it  may  be  distin- 
guished from  malic  and  oxalic  acids. 

TARTRATES.  Tartaric  acid  is  bibasic.  The  two 
tartrates  of  potassium  are  : 

Normal  potassium  tartrate,  K2C4H4O6 
Hydro  "  "          KC4H5O6. 

This  latter  salt  is  obtained  by  purifying  the  tartar 
of  wine  casks,  and  is  called  cream  of  tartar.  It  is  used 
in  the  preparation  of  black  flux,  white  flux,  potassium 
carbonate,  and  tartaric  acid,  also  largely  in  baking 
powders. 

KocEffiLLE  SALT.  KNaC4H4OG+4aq.  This  salt  is 
a  double  tartrate  of  potassium  and  sodium,  which  was 
formerly  much  used  as  a  purgative.  It  may  be  pre- 
pared by  mixing  in  a  porcelain  dish,  3500  grams  of 
water  and  1000  grains  of  cream  of  tartar,  this  is  brought 
to  boiling  and  sodium  carbonate  added  as  long  as  ef- 
fervescence is  produced.  This  solution  is  then  filtered 
and  evaporated  until  it  has  a  density  of  1.38. 

The  salt  crystallizes  in  regular  rhomboidal  prisms ; 
it  is  soluble  in  2£  times  its  weight  of  water,  but  in- 
soluble in  alcohol. 

TARTAK  EMKTIC.     Tartaric   acid  forms,  with  bases,  a 


EMETICS.  119 

a  class  of  salts  called  emetics,  the  type  upon  which 
they  are  formed  being  that  of  tartar  emetic.  The 
ordinary  tartar  emetic  has  been  generally  assigned  the 
formula  (SbO)'K=O2— C4H4O4,  in  which  the  monad 
radicle  stibyl  takes  the  place  of  one  of  the  basic  hydro- 
gen atoms.  It  is  prepared  by  boiling  for  an  hour  in 
100  parts  of  water,  12  parts  of  cream  of  tartar,  and  10 
parts  of  antimony  oxide.  This  mixture  is  then 
filtered,  evaporated  and  allowed  to  crystallize.  This 
salt  crystallizes  in  rhombic  octahedrons  ;  it  has  a  me- 
tallic taste,  a  slight  acidity,  and  is  soluble  in  14  parts 
of  cold,  and  about  2  parts  of  boiling  water. 

Crystals  of  tartar  emetic  effloresce  on  exposure  to  the 
air. 

A  strip  of  tin  precipitates  the  antimony  as  a  brown 
powder.  Tannin,  and  most  astringents,  precipitate 
the  antimony,  hence  tartar  emetic  should  not  be  ad- 
ministered in  connection  with  this  class  of  bodies. 
This  salt  is  the  most  used  of  the  antimony  compounds. 

FEERO -POTASSIUM  TAETBATE.- — Cream  of  tartar  is  di- 
gested with  ferrous  hydrate  for  two  hours  at  a  tem- 
perature of  60°.  For  every  100  parts  of  cream  of  tar- 
tar, a  quantity  of  hydrate  should  be  used  containing  43 
parts  of  ferrous  oxide. 

The  product  is  filtered,  Jhe  liquid  received  in  shallow 
plates,  and  kept  at  a  temperature  of  about  45°;  the  salt 
thus  crystallizes  in  brilliant  scales  of  a  garnet  red  color. 
It  dissolves  in  water,  but  is  insoluble  in  strong  alcohol. 
Tartaric  acid  is  often  adulterated  with  alum,  potassium 
bi sulphate  and  cream  of  tartar  ;  these  substances  may 


120  ORGANIC    CHEMISTRY. 

all  be  detected  by  means  of  alcohol,  in  wliich  they  are 
not  soluble. 

Tartaric  acid  is  used  in  making  effervescing  drinks, 
and  as  a  discharge  by  calico  printers. 

Tartaric  acid  produces  the  same  toxical  effects  as 
oxalic  acid,  though  requiring  much  larger  doses.  The 
blood  of  the  poisoned  person  becomes  red  and  very 
fluid. 

CITRIC     ACID. 


This  acid  is  found  associated  with  oxalic  and  tartaric 
acids  in  many  plants.  It  occurs  in  cherries,  currants, 
raspberries,  oranges  and  lemons. 

It  is  ordinarily  extracted  from  the  juice  of  lemons. 
This  juice  is  allowed  to  stand  until  fermentation  com- 
mences, then  filtered  and  treated  with  chalk  and  milk 
of  lime ;  an  insoluble  citrate  of  calcium  is  formed,  which 
is  decomposed  by  sulphuric  acid;  the  calcium  sul- 
phate is  filtered  off  and  the  filtrate  evaporated  and  left 
to  crystallize.  Citric  acid  crystallizes  in  regular 
rhombic  prisms;  it  is  soluble  in  three  fourths  its 
weight  of  cold  water;  this  solution,  in  time,  becomes 
covered  with  mould. 

Citric  acid  is  soluble  in  alcohol  and  ether.  Heated 
to  about  175°  it  furnishes  aconitic  acid, 

(1    II    ()   =  ^6  "-3  ®3   I    O 
V-/IJ-l''  ^ 


CITRIC    ACID.  121 

losing  H2O  on  increasing  the  temperature.  Another 
pyrogenous  acid,  itaconic  add  C^H^C^  is  formed, 
which,  if  heated,  is  transformed  into  oitraoonw  acid 
isomeric  with  the  last  mentioned. 

Oxydizing  bodies  destroy  citric  acid,  carbon  dioxide, 
acetone,  etc.,  being  produced.  Fused  caustic  potassa 
resolves  it  into  acetic  and  oxalic  acids. 

C6H8O7  +  HaO=C2HaO4  +  2C2H4O2 . 

Oxalic  acid.  Acetic  acid. 

Citric  acid  is  tetratomic  and  tribasic.  It  may  be 
distinguished  from  oxalic  and  tartaric  acids  by  its  ac- 
tion on  lime  water,  which  it  does  not  precipitate  in  the 
cold,  but  if  boiled  with  an  excess  of  lime  water,  a  pre- 
cipitate of  basic  calcium  citrate  is  obtained. 

MAGNESIUM  CITKATE. — This  salt  is  prepared  by  treat- 
ing magnesium  carbonate  with  a  strong  solution 
of  citric  acid  and  precipitating  this  salt  with  alcohol. 
It  is  much  used  in  medicine  as  a  purgative. 

CITRATE  OF  IRON. — Hydrated  ferric  oxide  is  dissolved 
in  a  hike-warm  solution  of  citric  acid,  and  the  liquid 
evaporated  to  dry  ness. 

This  body  varies  in  its  composition ;  it  occurs  in 
brilliant  amorphous  scales,  of  a  garnet-red  color. 

AMMONIA  CITRATE  OF  IRON. — One  hundred  grams 
citric  acid  are  digested  for  some  time  with  a  quantity 
of  ferric  hydrate,  representing  53  grams  of  iron,  and 
16  to  20  grams  of  aqua  ammonia.  The  liquid  is  then 
filtered  and  evaporated  to  the  consistency  of  a  syrup, 


122  ORGANIC     CHEMISTRY. 

and  transferred  to  very  shallow  vessels  which  are 
placed  in  drying  ovens.  This  substance  solidifies  in 
scales,  if  the  temperature  at  which  it  is  dried  is  not  too 
high  and  the  layers  of  liquid  are  extremely  thin. 

LACTIC  ACID. 

C3H6O3  =  C3H4 )  n3 
H,HfC 

This  acid  was  discovered  by  Scheele,  who  extracted 
it  from  sour  milk.  It  exists  in  many  products  after 
fermentation,  as  sauerkraut,  beet  juice,  and  various 
vegetables,  also  nux  vomica.  It  is  found  in  many  ani- 
mal fluids,  in  the  blood  and  in  the  fluids  which  per- 
meate the  muscular  tissues.  It  is  to  this  body  that  the 
acid  reaction  of  sour  milk  is  due.  Lactic  acid  extracted 
from  flesh  forms,  with  certain  bases,  salts  which  differ 
in  solubility,  etc.,  from  those  formed  with  ordinary 
lactic  acid,  hence  this  acid  is  sometimes  called  paralac- 
tic  acid,  also  sarko-laMio  acid,  from  ffapxos  flesh. 

Lactic  acid  may  be  prepared  by  dissolving  sugar  of 
milk  in  butter-milk,  adding  chalk  to  the  mixture,  and 
allowing  it  to  stand  for  eight  or  ten  days  at  a  tem- 
perature of  30°  to  35° 

The  sugar  of  milk  is  sometimes  replaced  by  glucose, 
or  cane  sugar  and  fermentation  favored  by  the  addi- 
tion of  cheese. 

A  special  ferment  (lactic  ferment]  is  developed 
which  is  transformed  into  sugar  and  lactic  acid,  but 
the  fermentation  is  arrested  as  soon  as  the  liquid 


LACTIC    ACID.  123 

becomes  acid,  and  it  is  in  order  to  prevent  this  acidity 
that  an  excess  of  calcium  carbonate  or  sodium  bicar- 
bonate is  always  maintained. 

Wurtz  has  produced   this  acid   artificially  by  the 
action  of  platinum  black  on  propylglycol. 


02  +  C3II802=C3H603  +  H20. 

Propylglycol. 

Lactic  acid  is  a  colorless,  syrupy  liquid  ;  at  about 
130°  it  is  changed  into  the  anhydride  of  lactic  acid, 
CgHjoOg,  and  at  about  250°  it  furnishes  a  crystalline 
body  called  laotide  whose  formula  is  C3H4O2. 

Lactic  acid  posseses  the  property  of  dissolving  cal- 
cium phosphate.  The  lactates  are  soluble  in  water. 
Lactate  of  iron,  (CgHgOg^Fe,  is  employed  in  medicine. 

URIC  OR  LITHIC  ACID,  C5H4N4Oj. 

Discovered  in  1776,  by  Scheele. 

This  acid  exists  in  human  excretions,  and  in  those  of 
the  carnivora.  In  the  excretions  of  herbivora,  the  uric 
acid  is  replaced  by  hippuric  acid.  Uric  acid  is  present 
in  normal  human  urine  only  in  small  quantity.  The 
urine  of  sedentary  persons,  and  of  those  whose  food  is 
very  nitrogenous  and  quite  substantial,  contains  more 
of  this  substance  than  that  of  individuals  who  lead 
an  active  life,  and  whose  diet  is  less  nourishing.  In 
the  latter  case  the  uric  acid  is  oxydized  and  converted 
into  urea,  hence,  the  proportion  of  the  acid  decreases 
as  the  quantity  of  urea  increases  :  whereas  calculi  of 


124  ORGANIC     CHEMISTRY. 

uric  acid  are  frequently  formed  in  persons  whose  diet 
is  very  nourishing,  and  whose  occupation  necessitates 
but  little  muscular  exertion.  The  excreta  of  birds 
contains  a  large  proportion  of  uric  acid,  and  that  of 
snakes  is  formed  almost  exclusively  of  this  body. 

This  acid  may  be  prepared  by  boiling  a  dilute  al- 
kaline solution  with  guano,  excreta  of  the  boa  con- 
strictor, or  uric  calculi  finely  pulverized. 

The  liquid  is  filtered  and  the  filtrate  supersaturated 
with  hydrochloric  acid ;  the  uric  acid  precipitates  in 
flakes,  which  become  crystalline  on  standing. 

The  author  having  had  occasion  in  1858  to  prepare 
large  quantities  of  uric  acid  from  guano,  found  that  in 
order  to  obtain  the  purest  product,  as  free  from  color- 
ing matter  as  possible,  it  was  preferable  to  use  sod- 
dium  hydrate  as  a  solvent,  and  carbon  dioxide  as  a  pre- 
cipitant,  the  latter  in  sufficient  excess  to  transform  the 
hydrate  into  bicarbonate. 

Crystals  of  uric  acid  are  colorless  and  odorless. 
They  are  nearly  insoluble  in  ether  and  alcohol. 
About  1500  parts  of  boiling  water  are  necessary  to 
dissolve  one  part  of  the  acid. 

On  distillation  uric  acid  yields  urea  and  other  cy- 
anic compounds.  Uric  acid  heated  with  water  and 
lead  dioxide  furnishes  urea  and  a  substance  called  al- 
lantoin,  which  has  been  found  in  the  urine  of  sucking 
calves.  Its  formula  is  C.4H6K4O3. 

The  same  derivative  of  uric  acid  was  obtained  by 
the  author  in  1858,  also  parabanic  acid,  on  heating  uric 
acid  with  manganese  dioxide  and  sulphuric  acid. 


URIC    ACID.  .       125 

If  1  part  of  uric  acid  be  added  to  4  times  its  weight 
of  nitric  acid  of  a  specific  gravity  of  1.45,  the  solution 
being  kept  cool,  small  crystals  of  a  substance  called 
alloxan  separate  out.  whose  formula  is 

C4H4N2O5+3H20. 

"Woehler  and  Liebig  obtained  from  this  body  a  num- 
ber of  very  interesting  derivations,  alloxantin,  al- 
loxanic  acid,  parabanio  acid,  thionuric  acid,  dia- 
luric  acid,  and  finally  a  magnificent  purple  crystalline 
body,  murexide.  A  large  number  of  various  deriva- 
tives have  also  been  obtained  by  other  chemists, 
especially  Bayer.  The  rich  color,  murexide,  is  made 
use  of  in  detecting  uric  acid.  For  this  purpose,  traces 
of  uric  acid  are  heated  in  a  watch  glass  for  a  few 
minutes,  with  one  or  two  drops  of  nitric  acid  ;  the  ex- 
cess of  acid  is  evaporated,  and  the  dry  residue  exposed 
to  the  vapors  of  ammonia,  when  a  purple,  or  very 
beautiful  rose  color,  will  appear. 

HIPPURIC  ACID. 


The  urine  of  herbivora  contains  a  large  percentage 
of  this  acid,  which  also  exists  in  a  small  quantity  in 
human  urine.  A  frugivorous  diet  augments  the  pro- 
portion of  this  body.  It  is  prepared  by  boiling  the 
fresh  urine  of  the  horse  (hence  the  name,  from  ITTTTO?, 
a  horse),  or  better  from  that  of  a  cow,  with  milk  of 


126  ORGANIC    CHEMISTRY. 

lime,  which  is  then  filtered  and  evaporated  to  one- 
tenth  its  volume;  this  is  mixed  with  a  large  excess  of 
hydrochloric  acid  and  left  to  stand  30  or  12  hours. 
The  impure  hippuric  acid  which  precipitates  is  re-dis- 
solved in  soda  and  re-precipitated  with  hydrochloric 
acid.  Animal  charcoal  may  be  added  to  the  saline  so- 
lution if  the  brown  color  still  remains.  Putrid  urine 
yields  only  benzoic  acid.  Dessaignes  has  prepared 
this  acid  artificially  by  causing  zincic  glycocol  to  act 
on  benzoyl  chloride. 


2)2  -I-  2C7H5OC1= 
ZnCl2  +  2C2H3[NH(07H5OJO2. 

Hippuric  acid  crystallizes  in  colorless  crystals, 
which  require  600  parts  of  cold  water  for  their  solution, 
but  are  very  soluble  in  hot  water  and  alcohol. 

It  is  decomposed  at  240°,  benzoic  and  cyanhydric 
acids  being  found  among  the  products  of  distillation. 
Under  the  action  of  oxydizing  agents  it  furnishes  ben- 
zoic compounds;  with  nitrous  acid  it  yields  benzo-gly- 
colic  acid. 


ALKALOIDS.  127 


ALKALOIDS. 

ARTIFICIAL    BASES   OK    ALKALOIDS. 
PEIMAKY. 

CnH2n+3K 

Methylamine  C  H3N 

Ethylamine  C,H7:N 

Propylamine  C3H9X 

Butylamine  C4HUN 

Amylamine  C5H13X 

Caprylamine  -       C8H19N\ 

CnH2n+1K 

Acetylamine  -         C2H5N 

Allylamine  C3H7N. 


Phenylamine,  aniline  -  C6H7  N 

Toluidine      -  C7H9N 

Xylidine  -  C8HUN 

Cumidine  -  C9H13I(s", 


Phtalidamine 


128  ORGANIC    CHEMISTRY. 

CnH2n_nN. 
Naphthalamine  -      C10H»N. 

SECONDARY. 

Dimethylamine  -      C2H7  N 

Methylethylamine  C3H9  N 

Diethylamine  -      C4  HnN. 

TERNARY. 

Trim  ethy  lam  ine  C3H9  K 

Dimethylethylamine      -         -      C4HnN 
Methylethylamylamine  C8H9  N. 

PHOSPHINES. 

Methylphospliine  C  H5  P 

Dimethylphosphine  -     CoH7  P 

Trimethylphospliine    •  C3H9P. 

ARSINES. 
Triethylarsine  C6H15As. 

STIBINES. 

Triethylstibine  -  C6Hi5Sb. 


NATURAL    ALKALOIDS.  129 

PRINCIPAL  NATURAL  ALKALOIDS. 

OF    THE    CINCHONAS. 


Quinia,Quinicia  and  Qninidi 
Cinchonia  and  Cinchonidia 
Aricina 

OF  OPIUM. 


Morphia  -        -                  C1TH19N  O3 

Codeia  C^H^N  O3 

Thebaia  C19H21N  O3 

Narcotina  -     O^EL^N  O7 

Papaverine  -                             C^I^N  O4 

Narceia  -     CigHagN  O9. 


OF   THE    STRYCHNOS. 


Strychnia  -        CaiH^NaOa 

Brucia  -      -     C^HagNaO^ 

OF  THE    SOLANACE-*. 

Nicotina  C10H14N2 

Atropia    -  CnH^N  O3 

Hyosciamine  CnH^N  O3 

Solania     -  C43H71N  OJ6. 

OF    THE    HEMLOCK. 

Conylia  -     C8H15N. 


130  ORGANIC    CHEMISTRY. 

OF   PEPPER. 

Piperidine  -     C3HUN. 

MISCELLANEOUS. 

Aconitina  -       C.^H^N  O 

Yeratria      -  C^H^N-A 

Theobromine  C7  H8  N4O2 

CaiFeia  C8H10N4O2. 

The  first  organic  base  isolated  was  morphia,  obtained 
in  1816,  by  Sertuerner.  In  1819,  Pelletier  and  Ca- 
ventou  extracted  quiniafrom  cinchona  bark,  and  showed 
that  the  very  active  plants  used  in  pharmacy  owed  their 
energy  to  compounds  capableof  uniting  with  the  acids, 
and  of  forming  with  them  definite  crystallizable  salts. 

From  that  epoch,  the  number  of  organic  alkaloids  has 
become  very  considerably  augmented  ;  and  methods 
have  been  discovered  by  which  many  of  the  alkaloids 
are  prepared  artificially.  It  was  Fritsche  who,  in 
1840,  obtained  the  first  artificial  alkaloid  on  distilling 
indigo  with  potassa  ;  he  named  it  aniline.  Gerhardt 
by  similar  methods  prepared  quinoleine.  Cahours 
pipcrldine,  and  Chantard  toluidine. 

The  distillation  of  organic  matter  also  furnishes  al- 
kaloids. Thus  several  of  them  have  been  obtained 
from  ti  product  of  the  distillation  of  bones,  the  oil  of 
Dippel  ;  also  as  products  of  the  distillation  of  various 
other  organic  compounds. 


COMPOUND    AMMONIAS.  131 

A  very  general  method  is  due  to  Zinin,  which  con- 
sists in  causing  a  reducing  substance  to  act  upon 
nitrous  compounds  as  nitrobenzol,  for  example.  The 
nitrous  compound  is  introduced  into  an  alcoholic  solu- 
tion of  ammonium  sulphide,  and  the  mixture  allowed 
to  stand  ;  sulphur  is  soon  deposited,  and  the  hydrogen 
of  the  hydrogen  sulphide  combines  with  the  oxygen 
of  the  nitrous  compound.  Example: 

C6H5NO2  +  3H2S=2H,O  +  3S  +  C6H7N. 

Nitrobenzol.  Aniline. 

For  this  mode  of  reduction,  as  it  is  not  very  prac- 
tical, and  is  tedious  in  execution,  there  is  at  present 
substituted  the  action  of  iron  upon  acetic  acid,  or 
that  of  zinc  or  tin,  on  hydrochloric  acid. 

Wurtz  has  given  a  very  interesting  method,  which 
has  led  to  the  discovery  of  alkaloids  much  resembling 
ammonia,  for  that  reason  called  compound  ammonias. 
It  consists  in  causing  potassa  to  react  upon  the  cyanic 
ethers,  these  bodies  being  decomposed  much  like  cy- 
anic acid. 

Thus  methylamine  is  obtained  by  the  action  of 
potassium  hydrate  upon  cyanate  of  methyl  : 


CO 

N  +  2K1IO=K,C03+    H 


}  H 

te  Potassium  Methyl- 

yl.  carbonate.  amine. 

Hofmann   made  known,  very  shortly  after  the  pub- 


132  ORGANIC     CHEMISTRY, 

lication  of  Wurtz'  process,  a  method  for  the  prepara- 
tion of  the  compound  ammonias,  by  which  not  only  a 
simple  equivalent  of  hydrogen  is  replaced  by  the 
radicles  (CH3),  (GjHs),  etc.,  but  all  the  hydrogen  of 
the  ammonia.  Hofmann's  method  consists  in  causing 
ammonia  to  react  upon  hydrochloric  as  well  as  brom- 
hydric  or  iodhydric  ethers,  particularly  the  latter. 

Let  us  take,  as  an  example,  iodide  of  ethyl  in  con- 
nection with  the  study  of 


ETHYLAMINE. 


Ten  to  15  grams  of  iodide  of  ethyl  and  50  grams  of 
aqua  ammonia  are  heated  in  sealed  tubes  of  green  glass 
placed  in  a  water  bath.  The  following  reaction  occurs: 


When  the  liquid  has  become  homogeneous  it  is 
allowed  to  cool,  then  decomposed  by  a  solution  of  po- 
tassium hydrate,  the  vapors  being  collected  in  water, 
containing  hydrochloric  acid.  The  hydrochloric  acid 
solution  is  evaporated  to  dryness,  and  the  residue  treated 
with  pure  alcohol,  which  dissolves  the  chlorhydride  of 
ethylamine  and  leaves  in  an  insoluble  state  the  ammo- 
nium chloride  derived  from  the  excess  of  ammonia 
used.  The  solution  of  chlorhydride  of  ethylamine  is 
evaporated  to  dryness,  and  the  deliquescent  crystals 
obtained  decomposed  by  potassium  hydrate,  with  the 
aid  of  a  gentle  heat.  The  volatilized  product  is  con- 
densed in  a  cooled  receiver.  In  this  reaction  there  is 


CLASSIFICATION  OF  THE  ALKALOIDS.       133 

also  formed  diethylamine,  triethylamine  and  oxide  of 
tetrethylammonium  from  which-  the  ethylamine  is 
separated  by  distillation. 

It  may  be  obtained  more  readily  by  first  distilling 
1  part  potassium  cyanate  with  2  parts  potassium, 
sulphovinate,  then  by  decomposing  the  cyanic  ether 
obtained  with  a  boiling  solution  of  potassium  hydrate 
contained  in  a  flask  connected  with  a  cool  receiver. 

Ethylamine  is  a  limpid  liquid,  with  a  strong  odor 
resembling  that  of  ammonia.  It  has  not  been  solidi- 
fied. It  boils  at  18.7°,  and  dissolves  in  water,  producing 
a  very  caustic  solution.  Ethylamine  is  equally  soluble 
in  alcohol  and  ether.  It  is  combustible,  burning  with 
a  blue  flame,  yellow  at  the  margin. 

It  displaces  ammonia  from  its  combinations.  Its 
solutions  give  reactions  similar  to  those  of  ammonia; 
for  instance,  with  salts  of  copper  it  gives  a  bluish  white 
precipitate,  which  is  dissolved  in  an  excess  producing 
a  deep-blue  solution. 

It  differs  from  ammonia  in  the  following  reaction: 
ethylamine  precipitates  alumina  from  its  salts,  and 
the  precipitate  is  soluble  in  an  excess  of  ethylamine, 
•  which  is  not  the  case  with  ammonia. 

CLASSIFICATION   OF     THE     ALKALOIDS,   OR   ORGANIC     BASES. 

AMINES. — Hofmann  has  given  the  names  of  primary 
amines,  or  monamines,  to  ethylamine,  which  we  have 
just  studied,  and  the  compound  ammonias  in  which  a 
single  atom  of  hydrogen  has  been  replaced  by  a 
radicle. 


134  ORGANIC     CHEMISTRY. 

The  same  chemist,  having  prepared  ethylamine  by 
the    action    of   ethyl    iodide   upon    ammonia,  subse- 
quently succeeded  in  obtaining  diethylamine  by  similar 
means. 
.    The  reaction  is  the  following  : 

(  C2H5 

=X-  02H5,HL 
(H 

This  hydroiodide  obtained,  treated  with  potassium 
hydrate  or  lime,  furnishes  a  second  base,  which  is 
biethylammonia,  or  diethylamine ; 

iP  TT 
cX- 
H 

A  similar  compound  is, 

fC6H5 
Ethylaniline  C8HnN=N  -j  C2H5 . 


These  bases  have  been  given  the  name  of  secondary 
amines  or  imides. 

The  secondary  ammonias  are  attacked  by  ethyl  iodide 
and  other  ethers,  and  a  reaction  takes  place,  iden- 
tical with  that  which  gives  rise  to  the  primary  and 
secondary  amines  and  tertiary  amines,  also  called 
nitrile  bases,  are  thus  obtained. 


AMINES.  135 

Such  bodies  are: 

fC2H5 
Triethylamine  C6H15lSr=:NN  C2H5. 

[cya. 

fOH3 
Methylethylphenylamine  C9H13N=N  •{  C2H5. 

I   P  IT 

I  ^6-0-5 

These  bases  are  related  to  the  alcohols  in  the  same 

manner  as  the  primary  amines.     Thus  diethylamine  is 

derived  from  the  action  of  2  molecules  of  alcohol  on  1 

'  molecule  of  ammonia  and  the  elimination  of  2  mole- 

cules of  water: 

2(C2H6O)  +  NH3—  2H2O=C4H11N. 

In  like  manner  the  ternary  amines  may  be  consid- 
ered as  derived  from  3  molecules  of  alcohol  and  1  mole- 
cule of  ammonia  with  the  elimination  of  3  molecules 
of  water. 

There  are  also  bodies  built  upon  the  type  of  two 
and  three  condensed  molecules  of  ammonia,  and  are 
denominated,  respectively,  di-arnines  and  tri-amines;  as 

(  (c2H4y 

Secondary  ethylene  diamine  N2  <  (02114)", 


(  (C2H4)' 
Ternary  ethylene  diamine  N2  •<  (C.,HY)". 


136  ORGANIC    CHEMISTRY. 

Triethylamine  attacks  hydroiodic  ether,  and  there  is 
formed  the  compound  C8H20NI==N(C2H5)4l.  This 
body  treated  with  oxide  of  silver,  furnishes  an  oxy- 
genated quaternary  base, 

C8H20ISri  +  Ag  HO=Ag  I  +  C8H21NO. 

This  substance  is  very  caustic,  soluble  in  water  and 
acts  as  an  inorganic  alkaline  base  like  potassium 
hydrate,  with  which  body  it  is  also  analagous  in  com- 
position. 


(C2H5)4N 
H 


N)0 
H  \  U< 


AMIDES,  ALKALAMIDES. — The  amides  are  bodies  built 
upon  the  type  of  ammonia,  in  which  one  or  more  of  the 
hydrogen  atoms  are  replaced  by  an  acid  compound 

radicle;  thus, 


acetamide 


There  are  also  mixed  combinations  of  amides  and 
amines,  called  aTkalamides,  as 

(  C6H5 

acetanilide  N"  \  C2H3O. 
H 


ALKALOIDS.  137 


NATUKAL  ALKALOIDS. 

Many  of  the  natural  alkaloids  appear  to  possess  a 
composition  analogous  to  that  of  the  compound  am- 
monias. Some  are  not  attacked  by  iodide  of  ethyl, 
and  should  be  classified  among  the  ammoniums,  bodies 
having  the  same  relation  to  the  compound  ammonias 
as  does  ordinary  ammonium  hydrate  to  ammonia. 
Others  are  acted  upon  by  iodide  of  ethyl,  and,  from  the 
number  of  bases  furnished,  it  may  be  ascertained 
whether  they  belong  to  the  primary,  secondary  or  ter- 
nary compound  ammonias. 

The  properties  of  the  natural  alkaloids  in  general, 
resemble  those  of  the  artilicial  bases  or  alkaloids. 
They  contain  nitrogen;  those  that  do  not  contain  oxy- 
gen are  ordinarily  volatile,  while  those  with  oxygen  are 
non- volatile ;  they  are  very  soluble  in  alcohol,  ether 
and  chloroform. 

Certain  ones  are  dissolved  by  the  hydrocarbides, 
which  are  now  considerably  used  in  the  preparation  of 
the  alkaloids.  Water  does  not  dissolve  any  of  the 
artificial  alkaloids,  except  those  having  a  very  low 
molecular  weight,  like  ethyl  am  ine;  this  liquid,  how- 
ever, dissolves  cod eia and narceia  quite  readily.  "With 
the  exception  of  quinia  and  cinchonia,  they  turn  the 
plane  of  a  polarized  ray  of  light  to  the  left. 

They  react  like  ammonia,  or  potassa,  with  vegetable 


138  ORGANIC    CHEMISTRY. 

colors,  and  furnish,  with  platinum  bichloride,  crystal- 
lizable  double  chlorides,  little  soluble  and  yellow  in 
color.  They  combine  equally  well  with  auric  and  mer- 
curic chlorides. 

The  natural  alkaloids  have  ordinarily  a  bitter  taste. 
Among  their  salts  the  sulphates,  nitrates,  chlorides 
and  acetates  are  mostly  soluble,  while  the  oxalates., 
tartrates  and  tannates  are  insoluble. 

The  harmless  character  of  tannic  acid,  and  the  in- 
solubility of  the  compounds  formed  by  it,  with  the  al- 
kaloids, render  tannin  and  astringent  vegetable  sub- 
stances generally  very  efficacious  antidotes. 

The  precipitates  they  produce  are  soluble  in  acid  and 
alkaline  liquids. 

The  alkaloids  are  partially  precipitated  from  their 
solutions  by  potassa,  soda  and  ammonia.  Iodine  water 
and  solutions  of  iodine  in  potassium  iodide,  precipitate 
them  completely. 

According  to  Schultze,  the  liquid  obtained  by  add- 
ing antimony  perchloride  to  a  solution  of  phosphoric 
acid,  is  a  re-agent  which  precipitates  most  of  the  or- 
ganic bases. 

A  delicate  re-agent  for  the  alkaloids  is  the  double 
iodide  potassium  and  mercury.  According  to  Meyer, 
the  best  proportions  are  49  grams  of  potassium  iodide 
and  135  grams  of  mercury  dichloride,  to  1  litre  of 
water.  It  is  best  to  add  the  re-agent  to  ihe  solution 
of  the  alkaloid,  which  may  be  neutral,  acid,  or  even 
feebly  alkaline. 

It   must  be  borne  in  mind    that   the   presence  of 


NIOOTINA.  139 

sugar,  tartaric  acid  and  of  albumen  may  mask  the  reao 
tions  of  a  number  of  alkaloids. 


NICOTINA   OR    NICOTYLIA. 


Nicotina  is  obtained  from  tobacco  (J^icotina  taba- 
cum.)  For  this  purpose  a  decoction  of  tobacco  is  made, 
and  the  liquor  evaporated  to  a  syrup.  The  extract  is 
treated  with  twice  its  volume  of  85  per  cent,  alcohol, 
which  precipitates  the  salts  present  and  certain  organ- 
ic substances. 

The  alcoholic  solution  is  distilled  and  the  residue 
submitted  to  a  second  similar  treatment.  The  alco- 
holic extract  thus  obtained,  is  mixed  with  a  concen- 
trated solution  of  potassium  hydrate,  and  the  nicotina 
liberated  is  re-dissolved  in  ether.  This  ethereal  solu- 
tion is  evaporated  in  a  water  bath,  and  the  residue 
distilled  in  an  oil  bath,  in  an  atmosphere  of  hydrogen. 

Nicotina  is  a  colorless  liquid  when  pure,  remaining 
liquid  at  -10°,  boiling  at  about  24:5°,  with  decomposi- 
tion. It  has  the  odor  of  an  old  pipe.  Exposed  to 
the  air  it  becomes  brown,  then  resinous;  water,  alcohol 
and  ether  dissolve  it  ;  its  solutions  are  strongly 
levogyrate. 

Nicotina  is  a  powerful  base;  it  fumes  when  a  rod 
moistened  with  hydrochloric  acid  is  brought  near  it  ; 
it  precipitates  the  metallic  oxides.  Nicotina  requires 
two  molecules  of  a  monobasic  acid  for  saturation. 
The  chloride,  C10II14N2'2ll'Cl,  is  crystallizable,  though 


140  ORGANIC     CHEMISTRY. 

•deliquescent.  The  hydrogen  it  contains  is  not  replace- 
able by  methyl,  ethyl,  etc.  It  may  be  considered  as 
having  the  rational  formula, 

(C5H7)"' 


(C5H7)' ' '  being  the  compound  radicle  nicotyl. 
Proportion  of  nicotina  in  different  tobaccos  : 

Havana,  2.0  per  ct. 

Maryland,  2.3      " 

Virginia,  6.9       " 

Lothringen,  8.0      " 

(Schloesing.) 

POISONING    BY    TOBACCO   OR    BY    NICOTINA. 

The  injection  of  a  concentrated  decoction  of  tobacco, 
causes  serious  results  in  a  few  minutes  :  intense  head- 
ache is  produced,  with  nausea  and  vomiting,  violent 
pain  in  the  abdomen,  pallor,  and,  finally,  extreme 
prostration. 

An  infusion  of  tea,  unroasted  coffee,  or  any  astring- 
ent substance  (pulverized  nut-galls,  or  oak-bark)  are 
the  only  antidotes  known,  and  they  are  far  from  being 
wholly  reliable. 

The  pure  nicotina  is  one  of  the  most  dangerous 
poisons.  It  manifests  itself  immediately  on  being 
taken,  since  it  is  entirely  soluble  in  water. 

The  nervous  system  is  especially  affected.  Two  or 
.three  drops  suffice  to  cause  death. 


CONIA.  141 

Two  drops  introduced  into  the  throat  of  a  dog  will 
almost  instantaneously  cause  the  following  series  of 
symptoms  :  respiration  becomes  difficult,  the  animal 
staggers,  falls  without  the  power  of  rising  again, 
throws  the  head  back  and,  in  a  few  moments,  is  perfect- 
ly paralyzed,  and  death  ensues. 


PIPEKIDINE. 


There  has  been  obtained  from  the  pepper  (  Piper 
longum,  Piper  nigrum  or  Piper  cdudatum)^  a  body 
crystallizing  in  colorless  prisms  called  piperine,  whose 
formula  is  C17H19NO3.  It  is  a  neutral  substance. 
When  distilled  with  three  times  its  weight  of  soda- 
lime  it  furnishes  piperidine,  a  limpid  liquid  having 
the  taste  of  pepper,  and  also  its  odor,  soluble  in  water 
and  alcohol,  boiling  at  106°. 

This  body  is  alkaline  and  saturates  acids.  It  con- 
tains a  single  atom  of  hydrogen  replaceable  by  methyl, 
ethyl,  etc. 

CONIA,  CONYLIA,  OR  CONINE. 


This  body  is  obtained  from  hemlock  (Conium  mac- 
ulatum);  the  crushed  seeds  are  distilled  in  a  large  glas& 
retort,  with  a  solution  of  potassa,  or  soda,  whereupon  an 
alkaline  distillate  is  obtained.  The  distilled  product  is 
treated  with  a  mixture  of  two  parts  of  alcohol  and  one- 


142  ORGANIC     CHEMISTRY. 

part  of  ether,  which  dissolves  the  sulphate  of  coma  and 
leaves  the  insoluble  sulphate  of  ammonium.  The  ethe- 
real alcohol  is  separated  by  distillation,  potassa  is  added 
to  the  residue,  and  the  mixture  distilled.  Water  and 
conia  pass  over;  the  latter  is  dehydrated  with  po- 
tassa, and  rectified  in  vacito,  or  in  a  current  of  hydro- 
gen gas. 

Conia  is  a  colorless,  oily  liquid;  emitting  an  odor 
of  hemlock.  Water  dissolves  it  but  little,  and  this 
better  when  cold  than  warm.  It  is  very  soluble  in  al- 
cohol and  ether.  It  boils  at  about  210°,  yet  emits  va- 
pors even  when  cold,  for  if  a  glass  rod,  moistened  with 
hydrochloric  acid,  is  brought  near  it,  white  fumes  are 
produced.  It  is  a  monacidic  base,  very  alkaline,  and 
forms  crystallizable  salts.  One  of  its  atoms  of  hydro- 
gen is  replaceable  by  ethyl  or  methyl. 

This  base  is  very  poisonous.  According  to  Christi- 
ason,  ten  centigrams  would  suffice  to  cause  death.  It  is 
classified  among  the  narcotics;  its  action  is  charac- 
terized particularly  by  its  effect  on  the  organs  of  respi- 
ration and  the  left  ventricle  of  the  heart. 

ALKALOIDS   OF   THE    PAP  AVERAGES. 

The  poppy-seed  capsules  ( Papaver  somniferum} 
yield,  on  incision,  a  milky  sap,  which  dries  up  in  a  day 
or  two ;  this  sap,  when  solidified,  constitutes  opium. 
There  are  three  leading  varieties  of  opium  : 

I.  Opium  of  Smyrna,  is  found  in  small  cakes  of 
100  to  150  grams,  frequently  distorted  and  agglutinate  <1 
together  by  reason  of  their  soft  nature,  and  contain  7 


OPIUM.  143 

to  10  per  cent,  of  water.  The  surface  is  brown,  but  the 
interior  has  a  fawn  color.  Sometimes  it  is  found  to 
contain  14  to  15  per  cent,  of  morphia,  but  in  other  in- 
stances only  5  to  6.  Good  Smyrna  opium  should  con- 
tain not  less  than  10  per  cent. 

II.  The  opium  of  Constantinople  is  drier  than  the 
preceding.     It  appears  in  commerce  in  flattened,  irreg- 
ular cakes,  almost  always    surrounded   with  poppy- 
leaves.     It  contains  5  to  10  per  cent,  of  morphia. 

III.  The  opium  of  Egypt  is  still  dryer ;  it  is  rarely 
enveloped  in  leaves.     Its  odor  is  feeble,  and  it  contains 
no  more  than  2  to  7  per  cent,  of  morphia. 

Recently,  attempts  have  been  made  to  cultivate  the 
poppy  in  Europe,  especially  in  France. 

Opium  contains  the  alkaloids  morphia,  codeia,  the- 
baia.  papaveririe,  opianine,  narcotine  and  narceia,  an 
acid  combined  with  these  alkaloids  called  meconic  acid 
(from  WKKJV,  a  poppy),  a  crystallized  neutral  substance 
called  meconine,  which,  according  to  Berthelot,  is  a 
complex  alcohol,  and  finally,  various  gummy  and  resin- 
ous compounds. 

MORPHIA   OR    MORPHINE. 

C17H19N03,H20. 

PREPARATION.  Ten  kilos,  of  opium  are  treated  re- 
peatedly with  water,  and  the  liquors  evaporated  to  the 
consistency  of  a  syrup. 

The  mass  is  redissolved  in  water,  filtered,  and  again 
evaporated.  To  the  lukewarm  liquid  are  added  1200 


144  ORGANIC    CHEMISTRY. 

grams  of  anhydrous  calcium  chloride,  dissolved  in 
twice  its  weight  of  water.  A  complex  precipitate  is 
formed,  containing  resins,  coloring  matters,  and  sul- 
phate and  meconate  of  calcium,  which  is  thrown  upon 
a  filter. 

The  filtered  liquid  is  evaporated  over  a  water-bath. 
During  the  concentration,  a  fresh  quantity  of  meconate 
of  calcium  is  separated  by  filtering,  and  the  liquid 
evaporated  to  the  consistency  of  syrup.  The  liquid  is 
then  acidulated  with  a  small  quantity  of  hydrochloric 
acid,  arid  set  aside  in  a  cool  place. 

At  the  end  of  a  few  days,  it  contains  brown  crystals 
of  the  double  chlorhydrate  of  morphia  and  codeia,  con- 
taminated with  a  blackish  liquid;  these  crystals  are 
drained,  pressed,  and  again  dissolved  in  as  little  boil- 
ing water  as  possible.  The  chlorhydrate,  on  coolingr 
deposits  crystals,  which  are  again  dissolved  in  hot 
water  and  decolored  with  animal  charcoal.  After 
heating  to  80°  or  85°,  the  solution  is  filtered,  and  the 
liquid,  on  being  concentrated,  deposits  the  double  chlor- 
hydrate in  pure  white  crystals. 

This  salt  is  again  dissolved  in  boiling  water,  and  the 
hot  liquid  treated  with  ammonia  ;  the  codeia  remains 
in  solution,  while  the  morphia  is  precipitated.  This 
deposit  is  thrown  upon  a  filter  washed  with  cold  water, 
dried,  and  dissolved  in  boiling  alcohol ;  the  morphia 
separates  out  in  crystals  on  cooling. 

It  frequently  contains  some  narcctfina,  from  which 
it  is  freed  by  washing  once  or  twice  with  ether,  or 
chloroform,  which  dissolves  the  narcotina,  and  does 
not  affect  the  morphia. 


MORPHIA.  145 

Pure  morphia,  (from  Morpheus,  in  allusion  to  its  nar- 
cotic qualities,)  crystallizes  in  regular  prisms  with  a 
rhombic  base,  is  colorless,  soluble  in  500  parts  of  boil- 
ing water,  scarcely  soluble  in  cold.  Forty  to  forty-five 
parts  of  cold  90  per  cent,  alcohol  are  required  to  dis- 
solve one  part  of  morphia ;  it  is  insoluble  in  ether. 
Solutions  of  morphia  are  very  bitter. 

Morphia  is  little  soluble  in  ammonia,  while  it  is  dis- 
solved very  readily  by  alkaline  solutions,  and  even  by 
lime  water. 

Under  the  action  of  heat,  it  fuses  in  its  water  of 
crystallization,  the  latter  escaping,  and  the  alkaloid  re- 
crystallizes  on  cooling. 

Morphine  is  an  energetic  reducing  agent,  reducing 
gold  and  silver  salts,  setting  free  the  respective  metals. 
It  separates  the  iodine  from  solutions  of  iodic  acid. 
If  a  solution  of  starch  is  poured  into  a  test-tube,  and  a 
solution  of  iodic  acid  and  traces  of  morphia  added,  the 
blue  color  of  iodide  of  starch  appears. 

If  morphia  is  put  into  a  few  drops  of  a  concentrated 
and  slightly  acid  solution  of  a  ferric  salt,  a  beautiful 
blue  color  is  produced,  which  subsequently  changes  to 
green. 

Morphia,  moistened  with  nitric  acid,  is  colored 
orange-red,  which  rapidly  changes  to  yellow. 

These  four  reactions  are  characteristic  of  morphia. 

If  iodine  and  morphia  are  mixed  in  equal  propor- 
tions and  the  mixture  treated  with  boiling  water,  a 
brown  liquid  is  formed  which  deposits  a  reddish-brown 
powder  called  iodomorphia.  Morphia  fused  with  al- 


146  ORGANIC     CHEMISTRY. 

kalies  yields  methylamine.  (p.  127).  It  is  attacked  by 
ethyl  iodide  at  100°,  a  single  molecule  of  ethyl 
entering  into  the  group. 

Morphia  forms  crystallizable  salts, from  the  solutions 
of  which  it  is  precipitated  by  the  fixed  alkalies. 

CHLORHYDRATE  OF  MORPHIA,  CnHigNOgHCl+SH^O. 
To  prepare  this  salt,  100  parts  of  pulverized  morphia 
are  treated  with  a  little  warm  water,  then  hydrochloric 
acid  is  added  in  sufficient  quantity  to  dissolve  the  al- 
kaloid. The  solution  is  afterwards  evaporated  in  a 
water  bath  until  it  crystallizes. 

This  salt  is  soluble  in  20  parts  of  cold  water,  very 
soluble  in  alcohol.  It  is  the  salt  of  morphia  most 
used,  and  contains  76  per  cent,  of  morphia. 

SULPHATE  OF  MORPHIA,  (C17H19J^O3)2Il2SO4+5H2O 
is  prepared  like  the  preceding  salt,  which  it  resembles 
in  appearance  as  well  as  in  properties. 

Morphia  and  its  salts  are  used  in  very  small  doses, 
as  in  larger  doses  they  are  energetic  poisons. 

CODEIA,  CwHaNOaJIaO. 

Discovered  in  1832  by  Robiquet.  This  base,  whose 
name  is  derived  from  xa?#7;,poppy  head,  exists  in  the 
ammoniacal  solution  obtained  in  the  preparation  of 
morphia.  On  evaporation  the  ammonia  is  driven  off 
and  the  codeia  is  precipitated  by  potassa.  The  codeia 
is  at  first  precipitated  in  the  form  of  a  sticky  mass 
which  soon  becomes  pulverescent.  It  is  washed  with 
and  dissolved  in  hydrochloric  acid.  The  liquid  is  then 
boiled  with  washed  animal  charcoal,  and  the  codeia 
precipitated  with  pota<sa. 


NARCOTINA.  147 

Codeia  is  crystalline,  very  soluble  in  alcohol  and 
ether.  It  dissolves  in  80  parts  of  cold  and  in  20  parts 
of  boiling  water. 

Codeia  is  very  soluble  in  ammonia,  and  nearly  in- 
soluble in  potassa.  With  chlorine,  bromine  and  ni- 
tric acid  it  forms  products  of  substitution.  With 
iodine  it  furnishes  ruby-red  crystals,  whose  formula  is 


Codeia  is  somewhat  used  as  an  anodyne.     It  is  easily 
distinguished  from  morphia,  since: 

I.  Codeia  is  soluble  in  ether  and  ammonia. 

II.  It  is  insoluble  in  solutions  of  potassa. 

III.  It  does  not  reduce  iodic  acid  or  ferric  salts. 
IV..  Nitric  acid  does  not  impart  to  it  any  color. 


NARCOTINA,  C^ 

Narcotina  crystallizes  in  rhombic  prisms.  It  is  al- 
most insoluble  in  cold  water,  somewhat  soluble  in 
alcohol,  quite  so  in  ether.  It  fuses  at  170°,  and  is 
decomposed  before  reaching  200°.  Dilute  nitric  acid 
transforms  it  into  various  products  of  oxydation,  the 
most  important  of  which  are  meconine,  cotarnine 
and  opianic  acid  Narcotina  unites  with  acids,  but 
the  compounds  are  decomposed  on  evaporation. 

It  is  distinguished  from  morphia  in  that  it  does  not 
reduce  iodic  acid  and  ferric  salts,  and  from  codeia  in 
giving  with  nitric  acid  a  blood  red  coloration.  This 
substance  is  also  insoluble  in  potassa  and  ammonia. 
It  is  not  as  poisonous  as  morphia. 


148  ORGANIC    CHEMISTRY. 

THEBAIA. 
C19H21N03. 

This  alkaloid,  sometimes  called  paramorphia,  is  the 
most  poisonous  of  the  bases  of  opium. 

It  is  crystallizable,  insoluble  in  water,  soluble  in 
alcohol  and  ether.  Fuming  nitric  acid  attacks  it  in 
the  cold,  and  a  yellow  liquid  is  obtained,  which  be- 
comes brown  on  contact  with  alkalies,  and  which  dis- 
engages an  alkaline  vapor.  Concentrated  sulphuric 
acid  gives  it  a  red  hue. 

PAPAVEKINE. 


This  body  is  crystallizable,  insoluble  in  water,  quite 
soluble  in  boiling  alcohol  and  ether.  It  forms  crystal- 
line salts. 

Under  the  action  of  strong  sulphuric  acid  it  as- 
sumes a  deep  blue  color,  though  Hesse  and  Drag- 
endorff  have  recently  ascertained  that  when  absolutely 
pure  no  color  is  obtained,  the  ordinary  article  found 
in  trade  not  being  pure. 

NARCEIA. 


This  alkaloid  crystallizes  in  silky  needles,  insoluble 
in  ether,  soluble  in  alcohol  and  boiling  water,  little 
Holuble  in  cold  water.  It  forms  crystallizable  salts. 


OPIUM.  149 

Narceia  fuses  at  95°,  and  commences  to  decompose 
at  about  1 1 0°.  It  is  attacked  in  the  cold  by  concentrated 
sulphuric  acid,  a  red  liquid  being  produced  which 
rapidly  becomes  green,  especially  if  slightly  heated. 
The  best  means  of  distinguishing  narceia  is  to  cause  a 
solution  of  iodine  to  act  upon  the  pulverized  substance. 
According  to  Roussin,  the  operation  is  most  easily  per- 
formed with  one  part  of  iodine  and  two  parts  of  potas- 
sium iodide  dissolved  in  ten  parts  of  water.  A  blue 
color  is  produced,  which  disappears  on  coining  in  con- 
tact with  alkalies,  or  on  heating. 

PHYSIOLOGICAL  ACTION  OF  OPIUM.       NARCOTIC  POISONS. 

Opium  in  small  doses  is  a  very  highly-prized  ano- 
dyne. Continued  use  of  this  substance  produces  a 
peculiar  state  of  inebriation,  an  excited  sleep  and  hal- 
lucinations of  various  sorts. 

The  bodies  of  opium-eaters  are  lean  and  cadaverous, 
their  eyes  are  lustrous,  their  forms  bent;  their  appe- 
tite diminishes,  and  they  exist  only  by  increasing  the 
dose  of  the  poison  which  destroys  them.  In  larger 
doses  it  is  highly  poisonous,  and  acts  in  a  different 
manner  from  that  of  the  poisons  already  studied.  It 
may  be  considered  as  the  type  of  the  narcotic  poisons. 
It  is  not  unfrequently  used  for  criminal  purposes, 
and  the  imprudent  administration  of  laudanum  and 
other  solutions  of  this  substance  often  causes  serious 
effects. 

Claude  Bernard  has  made  a  careful  study  of  the  ac- 
tion of  the  various  alkaloids  of  opium  upon  the  system, 


150 


ORGANIC     CHEMISTRY 


and  has  tabulated  their  soporific,  toxic,  and  convulsive 
actions  as  follows  : 


Toxic. 

Thebaia, 
Codeia, 
Papaverine, 
Narceia, 
Morphia, 
Narcotina. 

Convulsive. 

Thebaia, 
Papaverine, 
Narcotina, 
Codeia, 
Morphia, 
Narceia. 

Soporific. 

Narceia, 
Morphia, 
Codeia. 

With-     ) 
out       V 
action.    I 

Those  at  the  head  of  each  column  are  the  most 
marked  in  the  respective  characteristic  action. 

Subjoined  are  tabulated  the  principal  chemical 
characteristics  of  the  opium  alkaloids  : 


WATER. 

ALCOHOL. 

ETHER. 

AMMONIA. 

Morphia. 

But  little    sol- 
uble. 

Quite  soluble. 

Almost    insol- 
uble. 

Nearly    insol- 
uble. 

Codeia. 

Soluble. 

Very  soluble. 

Very  soluble. 

Soluble. 

Warcotina. 

Insoluble. 

Soluble. 

Soluble. 

Insoluble. 

Thebaia. 

Insoluble. 

Soluble. 

Soluble. 

Insoluble. 

Papaverine. 

Insoluble. 

Soluble. 

Soluble. 

Insoluble. 

Narceia. 

Slightly  sol'ble 

Soluble. 

Insoluble. 

Insoluble. 

QUINIA. 

QUINIA   OR   QUININE. 


151 


This  alkaloid  was  .discovered  in  1820  by  Pelletier 
and  Caventou.  The  following  is  the  modern  process 
by  which  it  is  prepared. 

Yellow  Peruvian  bark  is  carefully  pulverized  and 
thoroughly  mixed  with  30  per  cent,  of  its  weight  of 
lime,  previously  slacked.  The  mass  is  then  lixiviated 
three  or  four  times  with  refined  petroleum  (petroleum 
ether)  or  amylic  alcohol,  (wood  spirit)  which  dissolves 
the  alkaloids. 


NITRIC    ACID. 


SULPHURIC     ACID. 


1ODIC   ACID. 


Soluble. 

Nearly  insoluble. 

Insoluble. 
Insoluble. 

Insoluble. 
Insoluble. 


Orange-red     color 
ation. 


Orange-red     color- 
ation, 

Blood -red     color- 
ation. 

Yellow  coloration. 


Colored  violet  on 
heating  with  di- 
lute acid. 

Colored  violet  on 
healing  with  di- 
lute acid. 

Yellow   coloration. 
Red  coloration. 

Dark- blue  color- 
ation. 

Red  color,  which 
becomes  green. 


Reduced. 


Is  not  reduced. 


Is  not  reduced. 


15*2  ORGANIC     CHEMISTRY. 

The  united  extracts  are  agitated  with  water,  acidu- 
lated with  sulphuric  acid,  making  the  liquid  enly 
slightly  acid. 

When  the  solution  is  completed,  animal  charcoal  is 
added,  and  the  liquid  brought  to  boiling,  filtered  while 
still  hot,  and  allowed  to  cool.  .  The  quinia  sulphate 
which  is  formed,  2(C2oH24N2O2),  H2SO4+7aq.,  being 
but  slightly  soluble,  is  deposited  on  cooling. 

After  being  allowed  to  stand  24  hours,  the  sulphate 
is  collected,  expressed  and  redissolved  in  as  small  a 
quantity  of  water  as  possible,  containing  a  few  drops 
of  sulphuric  acid. 

The  liquid  on  cooling,  deposits  crystals,  which  are 
dried  at  35°.  The  mother  liquors  are  treated  with 
ammonia,  or  sodium  carbonate,  which  precipitates  a 
certain  quantity  of  the  alkaloid.  The  precipitate  is 
lightly  washed  with  water,  redissolved  in  dilute  sul- 
phuric acid,  boiled  with  washed  animal  charcoal,  and 
allowed  to  cool.  A  second  crop  of  crystals  of  quinia 
sulphate  is  thus  obtained.  The  mother  liquor  contains 
cinchonia  sulphate.  This  sulphate  is  dissolved  in  30 
times  its  weight  of  boiling  water,  allowed  to  cool,  and 
a  slight  excess  of  ammonia  added. 

The  cinchonia  which  is  precipitated  is  collected  on 
a  filter,  and  washed  with  lukewarm  water  until  the 
nitrate  no  longer  gives  witli  barium  chloride  a  white 
precipitate  insoluble  in  acids;  it  is  then  dried  at  a 
temperature  of  30°  to  40°. 

Quinia  is  white,  amorphous  and  very  friable.     It 


SULPHATES    OF    QUIXIA.  153 

may  be  obtained  in  a  crystalline  condition,  by  adding 
an  excess  of  ammonia  to  a  dilute  solution  of  quinia 
sulphate,  and  allowing  tlie  solution  to  stand. 

This  crystallized  quinia  melts  at  57°,  losing  its  water 
of  crystallization,  solidifies  and  remelts  at  176°.  It 
requires  250  parts  of  boiling  and  460  parts  of  cold 
water  for  its  solution. 

It  dissolves  in  2  parts  of  boiling  absolute  alcohol,  2 
parts  of  chloroform  or  50  to  60  parts  of  ether.  Its 
solutions  are  very  bitter,  levogyrate,  and  for  the  most 
part  fluorescent. 

Heated  on  platinum  foil,  quinia  swells  up  and  in- 
flames, leaving  a  deposit  of  carbon.  Heated  with  po- 
tassa  it  produces  hydrogen  and  quinoleine;  (cinchon- 
lein);  it  also  furnishes  a  brown  compound  on  being 
triturated  with  iodine. 

Quinia  is  recognized  by  the  following  reactions.  It 
is. first  saturated  with  very  dilute  sulphuric  acid  and 
chlorine  water;  then  an  excess  of  ammonia  is  added, 
whereupon  a  green  color  is  obtained. 

On  adding  powdered  potassium  ferrocvanide  before 
the  aqua  ammonia  a  rose  coloration  is  produced,  which 
afterwards  becomes  dark  red. 

Quinia  has  a  basic  reaction;  it  forms  with  acids 
crystallizable  salts  from  which  the  alkalies  precipitate 
quinia.  It  is  a  base  which  saturates  two  molecules  of 
a  monobasic  acid. 

SULPHATES  or  QUINIA.  Two  sulphates  of  quinia  are 
known;  that  obtained  by  the  process  we  have  above 


154  ORGANIC    CHEMISTRY. 

described,  is  the  neutral  sulphate,  though  generally 
known  as  the  basic  sulphate.     Its  formula  is 


This  salt  contains  74.3  per  cent,  of  quinia. 

It  crystallizes  in  very  delicate  needles  belonging  to 
the  clinorhombic  system,  and  which  effloresce  in  dry 
air.  It  dissolves  in  30  parts  of  boiling  and  740  parts 
of  cold  water;  also  in  60  parts  of  cold  absolute  alco- 
hol. It  is  very  nearly  insoluble  in  ether.  Its  solu- 
tions are  extremely  bitter.  It  becomes  phosphorescent 
on  being  heated,  and  subsequently  fuses. 

Heated  in  the  air  it  burns,  leaving  a  carbonaceous 
residue. 

Ou  adding  quinia  to  water  acidulated  with  sulphuric 
acid,  it  rapidly  dissolves  and  another  sulphate,  often 
called  the  acid  sulphate,  is  formed,  whose  formula  is. 


It  is  on  account  of  the  difficult  solubility  of  the  pre- 
ceding salt,  and  the  great  solubility  of  this  latter  one,, 
that  we  cautioned  against  the  employment  of  ai*  excess, 

o  i        *j 

of  sulphuric  acid  in  the  preparation  of  quinia. 

This  salt  dissolves  in  11  parts  of  water  at  12°,  and 
in  9  parts  at  18°.  Sulphate  of  quinia,  heated  to  130° 
with  acidulated  water  for  several  hours,  is  transformed 
into  an  isorneric  dextrogyrate  base  called  quinicine, 
which  is  likewise  a  febrifuge. 

Medicinal  sulphate  of  quinia  always  contains  sulphate 


QUINIA.  155 

of  cinchonia,  and  its  presence  is  not  considered  fraudu- 
lent, even  when  it  contains  3.5  per  cent,  of  the  latter 
substance,  as  this  salt  is  necessarily  produced  in  the 
preparation  of  quinia.  Cinchonia  appears  to  be  of  little 
therapeutic  value,  and  is  often  added  to  sulphate  of 
quinia. 

This  adulterant  is  detected  by  weighing  out  0.5 
grams  of  the  salt,  and  adding  to  it  5  grams  of  ether. 
The  mixture  is  agitated  and  1.5  grams  of  concentrated 
ammonia  added.  If  no  cinchonia  is  present,  two  liquid 
layers  are  obtained  ;  if  it  is  present,  a  layer  of  this  al- 
kaloid is  formed  directly  above  the  ammonia.  Good 
commercial  sulphate  of  quinia  should  give  only  a  very 
thin  layer. 

The  amount  of  quinia  may  be  directly  determined 
by  decanting  and  evaporating  the  ethereal  solution,, 
and  weighing  the  residue.  This  result  may  be  verified 
by  replacing  the  ether  in  another  determination,  by 
chloroform,  which  dissolves  both  bases;  the  residue 
obtained  by  the  evaporation  of  this  liquid  furnishes  the 
weight  of  the  quinia  and  cinchonia  together. 

Sulphate  of  quinia  sometimes  contains  sulphate  of 
quinidia;  this  base  is  precipitated,  together  with  cin- 
chonia, by  ether.  Its  presence  may  be  detected  by 
dissolving  one  gram  of  the  sulphate  in  30  grams  of 
boiling  water,  and  adding  to  the  solution  ammonium 
oxalate.  Oxalate  of  quinidia,  which  is  the  only  soluble 
oxalate  of  these  bases,  remains  in  solution,  and,  on  fil- 
tering, a  bitter  liquid  will  be  obtained,  in  which  the 
quinidia  may  be  precipitated  by  ammonium  hydrate. 


156  ORGANIC    CHEMISTRY. 

In  case  sulphate  of  quinia  has  been  adulterated  with 
calcium  sulphate,  or  other  inorganic  substance,  it  may 
be  recognized  by  a  residue  which  will  be  obtained  on 
heating  the  sulphate  to  redness  on  platinum  foil. 

Sulphate  of  quinia  should  dissolve  in  80  per  cent. 
alcohol.  If  it  dissolves  in  water,  but  does  not  dissolve 
in  56  per  cent,  to  60  per  cent,  alcohol,  it  may  be  re- 
garded as  not  pure. 

If  adulterated  with  starch,  or  fatty  bodies,  a  clear 
solution  cannot  be  obtained,  even  in  very  large  quanti- 
ties of  water. 

Should  it  contain  sugar  it  will  emit  an  odor  of 
caramel  on  ignition,  and  blacken  in  contact  with  sul- 
phuric acid. 

Quinia  sulphate  to  which  salicin,  a  common  adulter- 
ant. has  been  added,  is  colored  red  by  sulphuric 
acid. 

Quinia  sulphate  is  chiefly  employed  in  cases  of  in- 
termittent fevers. 

CINCHONIA   OK    CINCHONIKE. 


Cinchonia  was  discovered  by  Duncan  in  1803,  though 
first  recognized  as  an  organic  base  by  Pelletier  and 
Caveiitou  in  1820. 

It  differs  from  quinia  in  containing  one  atom  less  of 
oxygen  ;  it  has  never  been  converted  into  quinia. 

It  is  prepared  in  the  same  manner  as  quinia,  but 


CINCHONIA.  157 

from  the  Gray  Peruvian  Bark.  Cinchonia  separates 
out  in  crystals  on  the  evaporation  of  the  alcohol  with 
which  the  calcic  precipitate  is  washed. 

The  crystals  of  cinchonia  are  collected,  allowed  to 
drain,  and  the  liquid  which  runs  off  will  furnish  addi- 
tional crystals  on  being  evaporated.  To  this  mother 
liquor  sulphuric  acid  is  added  in  excess,  and  the  solu- 
tion slightly  evaporated. 

The  first  crystals  obtained  are  sulphate  of  quinia, 
which  is  less  soluble  than  sulphate  of  cinchonia. 
When  nothing  remains  but  a  very  concentrated  mother- 
liquor,  the  cinchonia  is  precipitated  by  ammonia,  and 
freed  from  quinia  by  washing  with  ether.  The  quinia 
dissolves,  while  the  cinchonia  remains  insoluble. 

The  latter  crystallizes  in  brilliant  colorless  crystals, 
which  are  insoluble  in  cold  water  and  ether,  soluble  in 
2,500  parts  of  boiling  water,  in  30  parts  of  boiling  90 
per  cent,  alcohol,  and  40  parts  of  chloroform. 

Its  solutions  are  very  bitter  and  dextrogyrate. 

Cinchonia  melts  at  about  257°;  on  heating  to  a 
slightly  higher  temperature  in  a  current  of  nitrogen, 
or  hydrogen,  it  is  completely  sublimed. 

"With  chlorine'and  bromine,  it  furnishes  dichloride 
and  dibromide  of  cinchonia.  "With  iodine,  a  yel- 
low crystalline  body  is  obtained,  whose  formula  is 

0,011,^,01. 

Heated  with  fused  potassa,  it  produces  quinoleine. 

Cinchonia  has  an  alkaline  reaction.  It  unites  with 
acids,  forming  salts  which  correspond  to  the  salts  of 
quinia,  though  generally  more  soluble. 


158  ORGANIC     CHEMISTRY. 

Cinchonia  sulphate,  heated  to  about  135°,  furnishes 
the  sulphate  of  an  isomeric  alkaloid,  cinchonicia,  or 
cinchonicine. 

Cinchonia  is  employed  as  a  febrifuge  in  Holland,  and 
a  few  other  countries,  but  its  action  is  regarded  as  in- 
ferior to  that  of  quinia. 

QUINOIDINE. — Quinidia  is  a  base  obtained  from  the 
last  mother-liquor  in  the  preparation  of  quinia,  by 
precipitation  with  sodium  carbonate,  It  is  often  min- 
gled with  another  alkaloid,  cinchonidia  or  dnchoni- 
dine,  and  it  is  this  mixture,  containing  chiefly  quinidia, 
which  is  called  quinoidine  in  commerce. 

Quinidia  is  isomeric  with  quinia ;  it  melts  at  160°. 
It  is  difficultly  soluble  in  water,  very  soluble  in  boil- 
ing alcohol,  and  slightly  soluble  in  ether.  Its  solutions 
are  dextrogyrate.  Quinidia  acts  as  a  febrifuge.  With 
chlorine  and  ammonia,  it  gives  the  same  reactions  as 
quinia,  and  forms  corresponding  salts. 

Quinoidine  contains,  as  we  have  said,  cinchonidia,  a 
substance  isomeric  with  cinchonia.  This  body  is  crys- 
talline, fusible  at  about  150°,  almost  insoluble  in  water, 
slightly  soluble  in  ether  and  chloroform  ;  boiling  alco- 
hol is  the  best  solvent  for  cinchonidia. 


STRYCHNIA.  159 


ALKALOIDS  OF  THE  STRYCHNOS. 

The  two  chief  alkaloids  are  strychnia  and  brucia. 
Desnoix  extracted  from  the  nux  vomica  another  alka- 
loid, which  he  named  igasuria  ;  but  according  to 
Schutzenberger,  this  body  is  a  mixture  of  several 
bases. 

These  alkaloids  are  extracted  from  the  fruit  of  the 
Strychnos  nux  vomica  ;  from  St.  Ignatius'  beans,  fruit 
of  the  Strychnos  Ignatii  ;  from  the  wood  of  Coulevre, 
root  of  the  Strychnos  colubrina  ;  from  the  upas,  the 
poison  of  indian  arrows,  extracted  from  the  Strychnos 
tieutSj  from  the  False  Angustura  Bark,  also  from  the  bark 
of  the  Strychnos  nux  vomioa,  which  contains  princi- 
pally brucia. 

STRYCHNIA. 


vomica  is  pulverized  and  boiled  with  three  suc- 
cessive portions  of  water  containing  sulphuric  acid,  and 
these  decoctions  evaporated  in  a  water  bath.  When 
the  liquid  is  reduced  to  a  small  volume,  125  grams  of 
quicklime  slacked  to  a  thin,  paste  are  added  for  eacb 


160  ORGANIC     CHEMISTRY. 

kilo,  of  nux  vomica.  The  precipitate  is  collected  on  a 
cloth,  washed,  dried,  and  treated  with  90  per  cent,  al- 
cohol. 

The  alcoholic  solution  is  distilled  to  three-fourths  it& 
volume  and  left  to  crystallize.  The  crystals  obtained 
are  chiefly  strychnia  ;  these  are  allowed  to  drain,  then 
dissolved  in  water  containing  £$  its  weight  of  nitric 
acid,  and  the  solution  concentrated  in  a  water  bath. 

The  nitrate  of  brncia  remains  dissolved  and  the 
nitrate  of  strychnia  crystallizes  out.  These  crystals 
are  re-dissolved  in  water,  animal  charcoal  added,  the 
solution  brought  to  boiling  and  then  filtered. 

Ammonia  is  added  to  this  liqYiid,  the  precipitate 
washed,  dried,  and  dissolved  in  boiling  alcohol,  which 
deposits  the  alkaloids  on  cooling. 

This  method  is  at  present  very  advantageously  sup- 
planted by  the  process  given  for  the  production  of 
quinia,  which,  briefly  stated,  consists  in  treating  the  sub-- 
stance with  lime  directly  and  employing  a  solvent  for 
the  alkaloids,  which  is  insoluble  in  water,  such  as  petro- 
leum or  amylic  alcohol. 

Strychnia  crystallizes  in  octahedrons  or  in  prisms  of 
the  rhombic  system ;  they  are  colorless,  very  bitter,  and 
almost  insoluble  in  water  or  ether,  but  readily  soluble 
in  ordinary  alcohol  diluted  with  75  per  cent,  of  water. 
Strychnia  treated  with  potassa  furnishes  a  small  quan- 
tity of  quinoleine.  Iodide  of  ethyl  produces  with  this 
base  the  compound. 


BBUCIA.  ]61 

CaH5B(C8H6)Na08L 

Chlorine  gas  renders  even  a  dilute  solution  of  this 
alkaloid  turbid  and  the  liquid  becomes  acid;  this 
reaction  is  characteristic.  Bromine  also  forms  deri- 
vatives by  substitution.  Iodine  combines  directly  with 
the  molecule  of  strychnia. 

Strychnia  dissolves  in  strong  sulphuric  acid;  the  so- 
lution is  colorless  and  becomes  dark  blue  in  contact 
with  potassium  bichromate  or  lead  dioxide.  The 
color  rapidly  passes  to  red  and  finally  to  a  yellow. 

Strychnia  is  colored  yellow  by  hydrogen  nitrate 
only  when  it  contains  brucia,  a  trace  of  which  is  suf- 
ficient to  produce  the  change. 

Strychnia  forms  with  acids  crystallizable  salts. 
The  nitrate  CaII22N208,H.NO8  crystallizes  in  fine 
needles  very  soluble  in  hot  water. 

Strychnia  is  among  the  most  powerful  poisons,  2  to 
3  centigrams  being  sufficient  to  cause  death.  There  is 
believed  to  be  no  reliable  antidote  for  strychnia  though 
F.  M.  Peirce  claims  that  small  doses  of  prussic  acid 
are  efficient  for  the  purpose.  (44-'  68-335.) 

BRUCIA. 


To  obtain  this  alkaloid  the  alcoholic  liquids  from 
which  strychnia  has  been  removed,  are  saturated  with 
oxalic  acid  and  evaporated.  The  crystals  of  oxal- 
ate  of  brucia  which  are  formed,  are  washed  with  95  per 


162  ORGANIC     CHEMISTRY. 

cent,  alcohol  and  redissolved  in  water.  The  solution 
is  decomposed  by  lime,  the  precipitate  collected,  dried 
and  dissolved  in  boiling  alcohol;  brucia  then  crystal- 
lizes out  and  is  purified  by  two  recrystallizations. 

Crystals  of  brucia  are  large  and  of  the  clinorhornbic 
system;  they  are  soluble  in  alcohol,  insoluble  in  ether, 
but  soluble  in  850  parts  of  cold,  or  500  parts  of  boil- 
ing water. 

Concentrated  sulphuric  acid  strikes  a  rose  color  with 
brucia  which  afterwards  changes  to  green.  Nitric  acid 
colors  it  red,  and  if  heated  it  gives  off"  nitrous  ether, 
methyl  alcohol  and  carbon  dioxide. 

Brucia  is  much  less  poisonous  than  strychnia. 

It  may  be  distinguished  from  strychnia  by  its  reac- 
tion with  nitric  acid.  A  red  color  is  produced  by 
brucia,  which  passes  to  violet  on  the  addition  of 
stannous  chloride.  This  latter  coloration  does 
not  take  place  with  morphia.  Brucia  is  also  one  of  the 
best  reagents  for  nitric  acid. 

CUEAEINA. — From  the  arrows  of  the  Indians  living 
on  the  shores  of  the  Amazon  and  Orinoco,  a  brown 
resinous  matter  is  collected,  from  which  crystals  of  a 
substance  have  been  obtained  whose  poisonous  action 
is  exceedingly  rapid.  Preyer,  to  whom  we  owe  this 
discovery,  regards  its  formula  as  Ci0H15N,  and  has 
named  it  curarina. 

The  Indians  of  Dutch  Guiana  poison  their  arrows 
with  two  other  substances  no  less  dangerous:  urari 
and  tikunas.  These  three  substances  paralyze  the  ac- 
tion of  the  muscles  by  destroying  the  motor  nerves 


VERATRIA.  163 

(Claude  Bernard).  It  appears  that  urari,  though  a  fa- 
tal poison  when  introduced  into  the  blood  by  a  wound, 
may  yet  be  swallowed  with  impunity. 

DRASTIC  POISONS. 

We  shall  not  describe  the  preparation  of  the  follow- 
ing alkaloids,  on  account  of  their  minor  importance. 
The  process  in  general  is  similar  to  that  by  which  the 
preceding  ones  are  prepared:  The  alkaloid  is  dissolved 
in  an  inorganic  acid,  precipitated  by  a  base,  and  redis- 
solved  in  an  appropriate  solvent. 

The  roots  of  the  white  hellebore  ( Veratrum  alburn) 
and  its  seeds,  furnish  an  alkaloid  called  vwatria, 
C^H^N-jOg.  It  crystallizes  in  prisms  having  a  rhom- 
bic base.  They  are  very  bitter,  insoluble  in  water, 
soluble  in  alcohol  and  ether,  and  melt  at  115°.  Yera- 
tria  is  dissolved  by  strong  nitric  acid,  the  solution  be- 
ing violet.  Sulphuric  acid  colors  it  first  yellow,  then 
red. 

Three  other  poisonous  bases,  sdbadillia^  colchinia, 
and  jervia,  are  found  associated  with  veratria  in  the 
Veratrum  album.  Jervia,  C^H^NaOsSILjO,  (Ger- 
hardt  and  Wills'  analysis)  is  white,  crystalline  and 
fusible. 

These  bodies  are  very  corrosive  poisons,  producing 
great  irritation  of  the  alimentary  canal. 

ALKALOIDS   OF   THE    POISONOUS    SOLANACEJE. 

The  belladonna,  Atropa  belladonna,  and  the  thorn- 
apple,  Datura  stramonium*  furnish  each  an  alkaloid 


164  ORGANIC     CHEMISTRY. 

called,  respectively,  atropia  and  daturia,  the  formula 
of  which  is  CnHggNO,,. 

This  substance  crystallizes  in  fine  needles,  which  are 
fusible  at  about  90°,  and  are  partially  sublimed  at 
about  135°.  It  is  difficultly  soluble  in  water,  but  very 
soluble  in  alcohol  and  ether. 

Heated  with  an  oxydizing  agent,  such  as  potassium 
bichromate,  or  sulphuric  acid,  it  disengages  essence  of 
bitter  almonds,  easily  recognizable  by  its  odor,  andi 
crystals  of  benzoic  acid  are  sublimed.  With  sulphuric 
acid  a  violet  color  is  produced,  accompanied  by  a  fra- 
grant odor  resembling  that  of  a  rose. 

Hydrochloric  acid  furnishes  two  acids  with  atropia, 
tropic  C9H10O3,  and  atropic  C9TT8O2. 

Cases  of  poisoning  by  atropia  are  rare,  but  instances 
in  which  persons  are  poisoned  by  the  berries  of  bella- 
dona  are  of  frequent  occurrence. 

The  black  henbane,  Hyoscyamus  niger,  furnishes 
silky  needles  of  a  substance,  hyosoiamine^  which  has 
much  resemblance  to  atropia,  but  whose  action  as  a 
poison  appears  to  be  less  violent. 

Its  physiological  action  is  on  the  nerves  rather  than 
on  the  muscles.  It  causes  less  dilation  of  the  pupilof 
the  eye,  and  produces  a  sombre  delirium. 

Belladonna  and  atropia,  datura,  also  henbane  and 
hyosciamine,  as  well  as  the  poisonous  solanaceae  in 
general,  should  be  classed  among  the  narcotic  poisons. 

Poisoning  produced  by  belladonna,  and  by  most  of 
the  poisonous  solanaceae.  is  characterized  by  great  dila- 
tion of  the  pupils  of  the  eyes.  The  patient  is  also 


ACONITINA.  165 

seized  with  vertigo  and  strange  hallucinations  followed 
by  a  turbulent  delirium  and  convulsions.  The  face  is 
congested,  respiration  difficult,  and  the  skin  often 
breaks  out  in  an  eruption  similar  to  that  in  rubeola 
(measles). 

No  antidote  is  known  for  these  poisons;  an  infusion 
•of  unroasted  coffee,  tea,  or  other  astringent  substances 
is  recommended,  but  the  use  of  energetic  emetics  and 
purgatives  is  the  most  efficient  method  of  treatment. 

The  chemical  characters  of  these  alkaloids  has  not 
been  as  jet  very  fully  studied. 

Desfosse  has  extracted  from  the  woody  nightshade, 
Solanum  dulcamara,  from  the  berries  of  the  felon- 
wort  and  from  the  young  sprouts  of  the  potato,  Sola- 
num  tuberosum,  a  substance  called  solanine,  C43H7iN"O16, 
a  highly  poisonous  alkaloid.  On  being  boiled  with 
acids,  it  furnishes  a  stronger  base  solanidine  and 
glucose. 

ACONITINA. 

Aconitina  is  extracted  from  the  monk's-hood, 
Aconitum  napellus,  as  a  colorless  amorphous,  bitter 
powder,  soluble  in  alcohol,  slightly  soluble  in  ether,  and 
almost  insoluble  in  water.  It  fuses  at  120°,  and  is  al- 
kaline. It  is  a  very  active  poison.  Planta  gives  its 
formula  as  O3oH47NO7  (?). 

Duquesnel  has  extracted  from  the  Aconitum  napel- 
lus  a  crystalline  alkaloid,  whose  formula  is 


166  ORGANIC     CHEMISTRY. 

DIGITALIN. 

This  substance  was  long  ago  obtained  in  an  amor- 
phous condition  from  the  purple  fox-glove.  In  1871 
Nativelle  succeeded  in  obtaining  it  in  a  crystalline 
form.  An  extract  of  fox-glove  is  first  prepared,  con- 
centrated by  distillation  and  dilluted  with  3  times  it& 
volume  of  water. 

A  precipitate  is  formed  which  contains  two  bodies, 
digitalin  and  digltin.  This  deposit,  washed  wilh 
boiling  alcohol,  furnishes  crystals  composed  of  these 
two  substances,  which  are  easily  separated  by  chloro- 
form, as  digitalin  is  dissolved  by  it  in  all  proportions, 
while digi tin  is  insoluble. 

The  proportion  of  digitalin  in  Digitalis  grown  in 
different  countries,  has  been  made  the  subject  of 
special  investigation  by  Prof.  S.  P.  Duffield,  of 
Detroit.  (94-1868.) 

Digitalin  is  very  bitter  to  the  taste.  It  powerfully 
irritates  the  nostrils,  and  is  an  active  poison.  If  digi- 
talin be  moistened  with  strong  sulphuric  acid  and  then 
exposed  to  the  vapors  of  bromine,  it  assumes  a  purple 
color,  which  is  darker  or  lighter  according  to  the  pro- 
portions employed.  Hydrochloric  acid  produces  with 
digitalin  a  very  intense  emerald  green  color. 

One-fourth  of  a  milligram  is  sufficient  to  produce 
the  ordinary  poisonous  effects  oi  digitalis.  A  milli- 
gram produces,  in  from  three  to  five  days,  a  marked 
change  in  the  circulation.  Three  milligrams  produce 
most  dangerous  effects  within  24  hours. 


EMETIA.  167 

It  is  much  to  be  desired  that  physicians  substitute 
this  crystalline  substance,  which  is  invariable,  for  the 
amorphous  digitalin,  which  varies  greatly,  both  as  to 
character  and  effectiveness.  Tardieu  places  digitalin 
among  the  hyposthenic  poisons. 

Poisoning  by  digitalin  has  often  been  produced 
through  imprudence. 

The  upas  antiar,  with  which  the  Indians  poison 
their  arrows,  is  obtained  from  the  Antiaris  toxicaria. 

EMETIA. 

This  body  is  obtained  from  the  roots  of  the  ipecac- 
uanha, Cephcelis  ipecacuanha;  it  also  exists  in  the 
Richardsonia  braziliensis,  in  the  Pfisychtria  emetica, 
and  in  the  roots  of  the  Cainca  (madder  tribe).  These 
materials,  reduced  to  a  powder,  are  treated  with  con- 
centrated alcohol,  and  the  alcohol  then  distilled  off. 
The  extract  is  diluted  with  five  times  its  volume  of 
water,  and  filtered.  To  the  filtrate  2  per  cent,  of 
caustic  potassa  is  added,  and  this  mixture  agitated 
with  chloroform.  The  chloroform  is  decanted  and 
distilled  ;  the  emetia  separates  out.  It  is  dissolved 
in  dilute  sulphuric  acid,  and  precipitated  from  the  so- 
lution with  ammonia.  A.  Glenward  (105-[3]  6 — 201) 
gives  CisH^NCXj  as  the  formula  of  emetia. 

It  is  amorphous,  yellowish,  fusible  at  50°,  soluble 
in  water  and  alcohol.  Its  solutions  are  slightly  bitter. 
It  is  a  very  weak  base,  and  its  salts  are  not  crystalline. 
A  few  centigrams  suffice  to  produce  vomiting. 


168  ORGANIC     CHEMISTRY. 

CANTHAEIDIN 

is  a  very  poisonous  crystalline  substance,  obtained  from 
Spanish  flies,  (Lytta  vesicatoria,  and  other  varieties) 
and  has  the  composition  C5H6O2.  It  is  present  in 
nearly  all  parts  of  the  flies,  varying  in  amount  from  0.5 
to  1.2  per  cent.  R.  Wolff  has  of  late  given  this  sub- 
stance a  very  full  investigation.  (95,  May,  '77-1021.) 

CAFFEINE  (CAFFEIA)  OK  THEINE  (THEIA). 
C8H10N402,H20. 

Alcohol  is  added  to  a  mixture  of  5  parts  coffee  and 
1  part  slacked  lime,  until  nothing  further  is  dissolved, 
and  the  solution  distilled.  The  residue  is  treated 
with  water,  which  causes  an  oil  to  separate  out. 
The  watery  liquid  furnishes  crystals  which  are  puri- 
fied by  treating  with  animal  charcoal,  and  recrystal- 
lizing  in  hot  water. 

The  extractive  matters  of  the  kola-nut  and  mate  pos- 
sess the  same  properties  as  caffeine. 

Caffeine  crystallizes  in  fine  needles,  fusible  at  ITS0, 
and  is  volatile  at  a  slightly  higher  temperature.  These 
crystals  are  but  little  soluble  in  ether  and  cold  water, 
yet  dissolve  very  readily  in  alcohol  and  boiling  water. 

It  is  remarkable  that  the  instinct  of  man  should 
have  led  him  to  select,  as  the  bases  of  common  bever- 
ages, just  the  four  or  five  plants,  which  out  of  many 
thousands  are  the  only  ones,  as  far  as  we  know,  con- 
taining caffeine. 


THEOBROMINE.  169 

It  is  recognized  by  boiling  with  fuming  nitric  acid ;  ;i 
yellow  liquid  is  produced.  On  being  evaporated  to 
dryness,  and  ammonia  added  to  the  residue,  a  purple 
coloration  is  produced,  resembling  murexide.  (p.  125.) 
Amalic  acid  and  CholestropJian  are  products  of  the 
action  of  oxidizing  agents  upon  caffeine;  bodies  link- 
ing this  alkaloid  to  the  uric  acid  group. 

THEOBBOMINE. 

There  is  extracted  from  the  caco,  Theobroma  cacao,  a 
principle  crystallizing  in  microscopic  crystals,  volatile 
at  295° ,  soluble  in  alcohol  and  ether,  and  slightly  so  in 
water.  It  furnishes  salts  which  are  decomposed  by 
water.  It  is  called  theobromine ;  its  formula  is  C7Ha 
NA, 

PICROTOXIN. 

C5H602. 

From  the  Indian  berry,  Cocculus  Indicus,  there  is 
extracted  a  white  crystalline  matter  of  extreme  bitter- 
ness, called  picrotoxin,  (from  Ttinpos  bitter  Togixov.} 
This  body  is  neutral,  difficultly  soluble  in  water,  and 
easily  soluble  in  alcohol  and  ether;  its  solutions  are 
levogyrate. 

The  physiological  action  of  picrotoxin  is  analo- 
gous to  that  of  strychnia,  but  it  differs  from  it  in  that 
it  renders  the  action  of  the  heart  slower,  and  produces 
vomiting. 

Prof.  J.  W.  Langley,  of  Pittsburg,  has  contributed 


170  ORGANIC    CHEMISTRY. 

much  to    (87-1862)    our  knowledge  of  the  chemical 
character  of  picrotoxin. 

POLYATOMIC   ALKALOIDS. 

There  are  polyatomic  bases  which  are  to  the  mona- 
tomic  bases  what  polyatomic  alcohols  are  to  monatomic 
alcohols. 

They  are  built  upon  the  type  of  several  molecules 
of  ammonia,  or  condensed  ammonia,  in  the  same  man- 
ner that  polyatomic  acids  and  alcohols  are  derived 
from  several  molecules  of  water. 

Clocz  obtained  the  former  by  the  action  of  ethylene 
bromide  upon  potassa  dissolved  in  alcohol. 

Hoffmann  established  their  true  formula.  They  are 
called  poly  amines. 

EXAMPLE. 

(  C2H4' 

Ethylenic  diamiue,  N2  \      H2 
I      H2 

(  Call/  } 
Diethylenic       "       N2  1  02TT/  [ 


Triethylenic     «         N2  1  C2H4" 
~  I  C2H4" 


UREA. 

(  CO" 

4NoO=N.,  I  H2 

"  I  II, 


POLYATOMIC    ALKALOIDS.  171 

ftouelle,  Jr.,  was  the  first  to  obtain  this  body  in  an 
impure  state  from  urine. 

Fourcroy  and  Yanquelin  first  obtained  it  pure. 

Woehler,  in  1828,  prepared  it  artificially  by  a  remark- 
able synthesis,  the  first  attempt  to  form  a  body  syn- 
thetically. Urea  forms  the  chief  constituent  of  the 
urine  of  mammalia,  amounting  to  nearly  one-half  of  the 
solid  constituent;  a  small  proportion  of  urea  is  found 
in  all  the  fluids  of  the  body. 

It  is  an  excretory  product,  as  the  hydrogen  and 
carbon  which  have  taken  their  part  in  the  body,  escape 
mainly  in  the  form  of  water  and  carbon  dioxide,  so 
the  nitrogen  is  eliminated  from  the  system  chiefly  in 
the  form  of  urea. 

Urea  may  be  extracted  from  urine  by  evaporating- 
this  liquid  to  one-tenth  its  volume  and  adding,  after  it 
has  become  cold,  an  excess  of  nitric  acid.  Brown 
crystals  of  nitrate  of  urea  are  formed:  these  are  drain- 
ed, expressed,  re-dissolved  in  water  and  boiled  with 
animal  charcoal.  This  solution  is  filtered,  and  on 
evaporation  it  deposits  crystals  of  nitrate  of  urea. 
This  salt  is  then  dissolved  in  as  small  a  quantity  of 
water  as  possible,  and  the  solution  treated  first  with 
barium  carbonate,  then  with  a  strong  solution  of  potas- 
sium carbonate;  urea  is  set  free  and  barium  and  potas- 
sium nitrates  formed.  The  above  mentioned  salts  are 
added  as  long  as  effervescence  is  produced;  the  liquid 
is  then  evaporated  to  dryness,  and  the  residue  treated 
with  absolute  alcohol,  which  dissolves  only  the  urea. 
(J.  E.  Loughlin,  100-5-362.) 


ORGANIC     CHEMISTRY. 

The  synthetic  method  employed  by  Woehler,  con- 
sists in  preparing  cyanate  of  ammonia,  which  body  is 
isomeric  with  urea. 


CYANATE  OF  AMMONHJM=H4CN2O=::NH4—  O-(M. 

This  substance  changes  spontaneously  into  urea. 

Heat,  upon  an  earthen  plate,  28  parts  of  potassium 
ferrocyanide  and  14  parts  of  manganese  dioxide,  both 
finely  pulverized,  and  dry  until  the  mixture  becomes 
pasty;  when  cold,  the  mass  is  pulverized  and  treated 
with  water,  and  20  parts  of  ammonium  sulphide  added 
to  the  liquid,  which  is  now  evaporated  in  a  water  bath, 
and  the  residue  treated  with  boiling  alcohol.  On 
evaporating  the  alcoholic  solution,  crystals  of  urea  are 
deposited.  Urea  is  also  obtained  as  a  product  of  other 
reactions.  It  crystallizes  in  prisms  of  the  tetragonal 
system;  these  crystals  are  colorless,  without  odor,  and 
have  a  cooling  taste. 

It  is  soluble  in  its  own  weight  of  water  at  15°,  in  an 
•equal  weight  of  boiling  alcohol,  and  in  5  parts  of  cold 
•80  per  cent,  alcohol  ;  it  is  difficultly  soluble  in  ether. 
Its  solutions  are  neutral. 

Urea  fuses  at  120°;  at  about  150°  it  is  decomposed, 
yielding  ammonium  carbonate,  ammelide,  C3OH5N5, 
and  liuret,  CoOoH5N3. 

Oxydizing  agents  decompose  urea.  Chlorine  also 
'decomposes  solutions  of  urea  in  the  following  man- 
ner : 

3C12  +  ^2O  +  CH4N2O=6HC1  +  N3  +  CO2  . 

Urea  heated  to  140°  with  water  in  sealed  tubes,  is 
transformed  into  ammonia  and  carbon  dioxide: 


UREA.  173 

H 


This  transformation  likewise  occurs  when  urea  is 
heated  with  strong  sulphuric  acid,  or  fused  with  po- 
tassa,  also,  spontaneously,  in  presence  of  the  nitro- 
genous matters  of  the  urine. 

Urea  does  not  appear  to  unite  with  all  acids.  It  has 
not  yet  been  combined  with  carbonic,  chloric,  lactic  or 
uric  acids.  The  nitrate,  chloride  and  oxalate  of  urea 
are  crystalline. 

Urea  forms  combinations  with  mercury,  silver, 
and  sodium  oxides,  also  with  mercuric  and  silver 
nitrates,  etc. 


174  ORGANIC    CHEMISTRY. 


NATURAL  FATS  AND  OILS. 

The  fatty  bodies  are  very  widely  distributed  through- 
out the  vegetable  and  animal  kingdoms.  Some  are 
liquid,  others  are  more  or  less  solid.  Certain  oils  re- 
main liquid  exposed  to  the  air,  as  olive  oil;  others 
oxydize  and  thicken,  as  linseed  oil,  poppy  oil,  and 
nut  oils;  the  latter  are  called  siccative  oils,  and  are 
used  in  the  manufacture  of  varnishes,  printers'  ink, 
oil  cloth,  also  in  paints. 

Fats  and  oils  are  insoluble  in  water;  they  are  among 
the  very  few  bodies  which  are  wholly  insoluble  in 
this  menstrum;  they  are  also,  in  general,  difficultly 
soluble  in  alcohol.  They  generally  dissolve  in  ether, 
and  the  liquid  hydro-carbons.  Their  specific  gravity 
is  less  than  that  of  water.. 

Heat  destroys  them ;  acrolein  is  usually  formed 
associated  with  other  products. 

Since  oil  and  water  repel  each  other,  many  other 
substances  may  be  protected  from  moisture  by  simply 
coating  them  with  oil.  Shoe-leather  may  be  rendered 
water-proof  and  iron  protected  from  rusting  by  greas- 
ing. "Wood,  saturated  with  oil,  will  last  for  a  long 
time  when  buried  in  moist  ground. 

STEARIN  OR  STEAKINE,  (from  Greap,  suet)  C57H110O6, 
is  prepared  by  melting  suet  in  turpentine;  the  two 
other  proximate  principles  present,  are  precipitated, 


PATS    AND   OILS.  175 

while  the  stearin  e  remains  in  solution.  It  is  separated 
from  the  liquid  by  water,  and  purified  by  several  re- 
crystallizations  in  ether ;  it  fuses  at  71°,  and  solidifies 
at  50°. 

Berthelot  has  reproduced  stearine  synthetically,  by 
heating  3  parts  of  stearic  acid  with  one  part  of  glyc- 
erine, in  a  sealed  tube. 

.  This  synthesis,  as  well  as  other  researches,  estab- 
lishes the  fact  that  the  neutral  fats  are  compound 
ethers  of  glyceryl,  and  the  fatty  acids. 

On  account -of  the  heat  generated  by  oxidizable 
oils  when  exposed  to  the  air,  frequent  instances  of 
spontaneous  combustion  occur  when  cotton  rags,  or 
waste  soaked  with  oil,  are  allowed  to  remain  in  a  heap. 

Fats,  especially  if  mixed  with  nitrogenous  matter, 
become  acid,  rancid.  The  chemical  nature  of  this 
change  is  not  entirely  understood. 

OLEIN  OK  OLEINE,  is  the  chief  constituent  of  olive  oil 
and  fish  oil.  Berthelot  has  shown,  by  the  action  of 
oleic  acid  on  glycerine,  that  natural  oleine  is  a  mix- 
ture of  monoleine,  dioleine,  and  trioleine.  Oleine 
heated  with  a  small  quantity  of  mercury  nitrate,  or 
any  other  body  capable  of  furnishing  nitric  oxide,  be- 
comes solid,  owing  to  the  transformation  of  the  oleine 
into-  an  isomeric  body,  elaidine.  Siccative  oils  contain, 
instead  of  oleine,  another  principle  called  elaine. 

Neutral  fatty  bodies  and  other  ethers  of  glycerine 
are  decomposed  by  alkaline  solutions ;  a  combination 
with  water  takes  place,  glycerine  and  fatty  acids  are 
formed.  We  may  take  as  an  example,  stearin. 


176  ORGANIC    CHEMISTRY. 

• 

3KHO+C57H11006-3(K018H3502)-fC3H803. 

Alkalies,  therefore,  react  upon  the  ethers  of  glycerine- 
in  the  same  manner  as  do  the  ethers  of  glycol  and 
ordinary  alcohol.  This  reaction  is  called  saponificar 
tion,  and  soaps  are  salts  formed  by  stearic,  inargaric,, 
and  oleic  acids,  with  a  metal. 

SOAPS.      STEAKINE  CANDLES. 

The  only  soluble  soaps  are  those  whose  base  is 
potassa  or  soda.  Soda  soaps,  those  ordinarily  in  use, 
are  hard,  while  potassa  soaps  are  soft.  On  adding  to 
an  aqueous  solution  of  soap  a  solution  of  a  metal,  a 
precipitate  is  formed  which  is  the  soap  of  the  metal 
employed  ;  thus  the  precipitate  which  common  water 
produces  in  soap  is  a  lime  soap. 

Ordinary  soap  is  made  by  boiling  fats  of  inferior 
quality  with  an  alkaline  solution.  When  the  oil  is 
completely  decomposed  the  soap  is  precipitated  by 
salt  water,  in  which  soap  is  insoluble. 

Stearin e  candles  have  hitherto  been  made  by  saponi- 
fying suet  or  tallow  with  lime  in  the  presence  of  boiling 
water.  At  present  the  amount  of  lime  employed  in 
the  saponification  is  considerably  diminished  (amount- 
ing to  only  4  per  cent.)  by  operating  at  a  temperature 
of  150°. 

The  saponification  of  fats  of  inferior  quality  is  also 
effected  by  means  of  sulphuric  acid  instead  of  lime; 
this  acid  forms  with  the  fatty  acids,  double  or  conju- 


FATS    AND    OILS.  177 

gate  acids,  which  are  decomposed  by  water.  The  de- 
composition of  fats  into  >  their  constituents,  the  fatty 
acids  and  glycerine,  for  the  manufacture  of  candles,  is 
at  present  effected  on  a  large  scale  by  simply  heating 
the  fats  with  steam  under  pressure,  and  at  a  tempera- 
ture of  260°.  This  is  the  celebrated  process  of  the 
American  inventor,  Tilghman,  to  whom  the  wonder- 
ful "  sand  blast "  is  also  due. 

This  decomposition  of  fats  is  most  remarkable,  as, 
by  the  same  process,  only  at  a  lower  temperature, 
Berthelot  obtained  a  result  exactly  the  reverse,  caus- 
ing stearic  acid  and  glycerine  to  reform  stearine  by 
simple  direct  synthesis. 

STEAKIC  ACID,  CjgH^Oa,  is  crystalline,  insoluble  in 
water,  soluble  in  alcohol  and  ether,  arid  melts  at  70°. 
It  unites  with  the  bases ;  its  alkaline  salts  alone  are 
soluble. 

MARGAKIC  ACID,  having  the  formula  C^H^C^,  (from 
^apyapov,  a  pearl,  owing  to  its  pearly  lustre)  is  crys- 
talline. It  melts  at  60°  and  forms  salts  with  the  metals. 

OLEIO  ACID,  C^HgjOo,  is  an  oil  becoming  colored  in 
the  air  and  converted  into  an  acid  called  elaidic  acid, 
which  is  fusible  at  44°,  in  contact  with  a  small  quantity 
of  hyponitric  acid. 

These  three  acids,  stearic,  margaric,  and  oleic,  are 
those  that,  with  glycerine,  constitute  most  of  the  natu- 
ral fats,  or  glyceryl  ethers. 

LEAD  PLASTER  is  essentially  a  lead-soap  compound 
of  plumbic  oleate. 


178  ORGANIC     CHEMISTRY. 

CKOTON  OIL. 

This  oil  is  extracted  from  the  seed  of  the  Croton 
tiglium  of  the  family  of  euphorbiacese. 

The  seeds  are  ground  and  expressed,  or  they  are 
treated  with  ether,  which  is  afterwards  driven  off  by 
distillation. 

This  oil  is  yellowish,  very  bitter,  and  possesses  a 
disagreeable  odor.  Alcohol  and  ether  dissolve  it.  It 
produces  blisters  whenever  it  comes  in  contact  with 
the  skin,  and  is  a  drastic  poison. 

Pelletier  and  Caventou  have  extracted  from  this  oil 
an  acid  body,  C4Ii6O2,  denominated-  crotonic  acid. 

COD-LIVEK  OIL. 

This  oil  is  extracted  from  the  liver  of  the  cod,  and 
several  other  species  of  the  genus  Gad^is.  Two  pro- 
cesses are  employed  for  its  extraction  ;  either  the  oil 
is  obtained  by  putrefaction,  in  which  case  the  oil 
separates  out  naturally,  or  the  livers  are  cut  into  small 
pieces  and  heated  in  large  pans,  then  placed  in  cloth 
sacks  and  pressed.  It  is  of  a  brownish  color.  A  white 
oil  is  sometimes  sold,  which  has  been  bleached  by 
treatment  with  weak  lye  and  animal  charcoal.  The 
efficiency  of  this  latter  oil  is  much  less  than  that  of 
the  natural  oil. 

There  has  been  found  in  this  oil  3  to  4  thousandths 
of  iodine,  and  a  small  quantity  of  phosphorous  ;  a7id 
its  medical  qualities  are  thought  to  be  due  to  these 


WAX.  179 

two  substances,  but  it  is  probable  that  its  efficiency  is 
more  frequently  due  simply  to  its  fatty  character. 

BUTTEK. 

Ordinary  Butter.  Butter  contains  stearic,  mar- 
garic,  oleic,  and  butyric  acids,  and  several  other 
proximate  neutral  principles.  Its  density  is  0.82.  It 
dissolves  in  30  per  cent,  of  boiling  common  alcohol. 
The  odor  which  it  emits  on  becoming  rancid  is  due  to 
the  liberation  of  fatty  acids. 

"  Oleo-margarine"  is  artificial  butter,  consisting 
mainly  of  oleine  and  margarine  obtained  from  suet  or 
lard. 

SPEBMACETT. 

This  substance  which  is  formed  in  peculiar  cavities 
in  the  head  of  the  sperm  whale,  and  is  a  neutral 
fatty  body  sometimes  employed  in  pharmacy.  It  is 
an  ether,  which,  on  saponification,  produces  a  fatty  acid 
called  ethalic  acid,  and  a  monatomic  alcohol,  ethal. 

H,0+0BHw08=C16HmOHO  +  C16HWO 

Spermaceti.          Ethalic  Acid.  E.hal. 

WAX. 

Fellow  bees-wax  is  obtained  by  submitting  honey- 
comb to  pressure,  then  fusing  the  same  under  boiling 
water.  It  is  bleached  by  being  cut  into  thin  cakes 
and  exposed  to  the  air  and  sunlight.  Thus  prepared 


180  ORGANIC     CHEMISTRY, 

it  fuses  at  62°.     Mixed  with   3  per  cent,  of  oil   of 
sweet  almonds  it  forms  a  cerate,  used  in  pharmacy. 

On  being  treated  with  alcohol  it  separates  into  two 
proximate  principles:  one,  soluble  in  this  liquid,  is 
acid,  and  is  called  cerotio  acid,  having  the  formula 
C27HMO;  the  other,  which  is  but  slightly  soluble,  is 
called  myricin.  The  latter  is  a  compound  ether, 
and  is  decomposed  by  bases  into  an  acid,  etkalic  acid, 
and  an  alcohol,  melissic  alcohol,  C^H^O. 

CASTOR  OIL. 

This  oil  is  extracted  from  the  Ricinus  co/nmunis,  a 
plant  of  the  family  of  Euphorbiaceae. 

The  castor-oil  beans  are  hulled,  pulverized,  and 
the  pasty  mass  obtained  subjected  to  strong  pressure. 
This  oil  is  slightly  yellow.  Its  density  is  0.926  at 
12°,  and  it  remains  liquid  at  a  temperature  of —18°. 
It  is  very  soluble  in  alcohol,  a  characteristic  which 
distinguishes  it  from  most  other  oils. 

This  oil  is  also  an  ether  of  glycerine;  the  acid  which 
it  contains  is  ricinoleic  acid,  CjgH^Os. 


SUGARS.  181 


SUGARS. 

The  general  name  of  sugars,  by  some  regarded  as 
polyatomic  alcohols,  is  given  to  bodies  which  are  capa- 
ble of  fermenting,  that  is,  of  decomposing  directly  or 
indirectly  into  different  products,  of  which  the  princi- 
pal ones  are  alcohol  and  carbon  dioxide.  Fermenta- 
tion requires  the  presence  of  certain  -microscopic 
plants,  and,  according  to  Pasteur,  is  a  phenomenon 
correlative  with  the  vital  development  of  these 
organisms.  This,  however,  has  been  latterly  dis- 
proved by  Tyndall. 

Sugars  may  be  divided  into  three  classes.  In  the 
first  are  those  in  which  the  proportion  of  hydrogen 
is  more  than  sufficient  to  convert  the  whole  of  the  oxy- 
gen into  water.  It  contains  : 

Mannite,  C6H14O6,  extracted  from  manna. 

Dulcite  or  mSla/mpyrite^  C6IIUO6,  found  in  Mada- 
gascar. 

Pinite,  06IIi->O5,  extracted  from  a  Californian  pine 
tree. 

Qu&roite,  C6H12O5,  extracted  from  acorns. 

These  bodies  do  not  ferment  with  beer  yeast  alone; 
but  in  presence  of  certain  ferments  and  calcium  car- 
bonate they  furnish  alcohol,  carbon  dioxide,  and  hy- 
drogen. 

Sugars  of  the  second  and  third  class  contain  hydro- 
gen and  oxygen  in  the  proportions  to  form  water. 


182  ORGANIC    CHEMISTRY. 

The  second  class  includes  the  glucoses,  isomeric 
bodies,  whose  general  formula  is,  C6H12O6.  Among 
these  are: 

Ordinary  Glucose  ex  grape  sugar. 

Levulose,  associated  with  glucose  in  the  form  of 
inverted  sugar. 

Maltose,  obtained  from  malt. 

Galactose,  obtained  by  treating  sugar  of  milk,  or 
gums,  with  dilute  acids. 

Eucalin,  obtained  by  the  action  of  maltose  on  beer 
yeast. 

Sorbin  exists  in  the  berries  of  the  mountain  ash. 

Inosite  is  found  in  the  embryo  of  young  plants 
and  in  the  fluids  of  flesh. 

Lactose  or  Sugar  of  Milk.  The  glucoses  may  be 
divided  into  two  series.  The  first  includes  those  bodies 
(ordinary  glucose,  levulose)  which,  on  being  oxydized, 
form  saccharic  acid,  and  on  being  hydrogen ized  by 
means  of  sodium  amalgam,  produce  mannite.  The 
second  includes  those  substances  (galactose,  lactose) 
which,  on  oxydation  produce  mucic  ac*id,  and  on  liydro- 
genation  furnish  dulc'de.  The  third  class  of  su- 
gars contains  bodies  whose  general  formula  is  C^IL^On, 
and  are  called  saccharoses,  by  Berthelot.  It  contains, 
besides  cane  sugar,  three  bodies  called: 

Melitose,  an  exudation  of  certain  eucalypti. 

Trehaluse  or  mycose.,  extracted  from  the  Turkish 
manna  and  certain  mushrooms. 

Melezitose,  obtained  from  an  exudation  of  the  larch. 

The  sugars  of  the  first  two  classes  are  placed  by 
Berthelot  among  the  polyatomic  alcohols. 


MANNITE.  183 

MANNITE. 

C6H14O6. 

This  body  exists  naturally  in  an  exudation  of  vari- 
ous species  of  ash  (FravdnuB  rotundifolia),  called 
manna,  of  which  it  forms  the  greater  portion.  It  is 
also  found  in  mushrooms,  algae,  the  sap  of  most  fruit 
trees,  onions,  asparagus,  celery,  etc.  It  may  be  pre- 
pared by  dissolving  manna  in  one-half  its  weight  of 
water,  to  which  a  small  quantity  of  egg  albumen  is 
added,  and  the  mixture  brought  to  boiling  and  filtered. 
On  cooling,  colored  crystals  are  deposited  which  are 
expressed  and  redissolved  in  hot  water.  This  solution 
is  mixed  with  animal  charcoal,  boiled  and  filtered  while 
hot.  The  liquid  deposits  crystals  on  cooling.  Man- 
nite  crystallizes  in  rhombic  prisms  and  has  a  sweet  taste. 
It  dissolves  in  seven  times  its  own  weight  of  cold  wa- 
ter, is  slightly  soluble  in  alcohol,  and  insoluble  in  ether. 
Its  solutions  are  optically  inactive. 

Mannite  fuses  at  about  165°;  at  about  200°  it  yields 
a  certain  quantity  of  a  substance  called  Mannitane, 
C6II12O5.  It  oxydizes  in  presence  of  platinum  black, 
furnishing  a  non-crystallizable  acid  called  mannitic 
acid.  Boiling  nitric  acid  converts  it  into  saccharic 
and  oxalic  acids. 

Mannite,  treated  with  a  small  quantity  of  nitric  acid, 
is  changed  into  a  body  insoluble  in  water,  called 

nitro-mannite,  /-\r6n  \   f  O6,    wmcn  mav  be  regarded 

(^>U2)6  ) 

as  a  compound  ether. 

Dulcite. — Dulcite  is  very  analogous  to  mannite,  but 
differs  from  it,  in  that  it  furnishes,  with  nitric  acid, 
mucic  acid. 


184  ORGANIC     CHEMISTRY. 


GLUCOSES. 

C6H1206. 

These  compounds  may  be  considered  as  representa- 
tive carbohydrates.  Ordinary  glucose  (from  yX.vKV$, 
sweet,)  or  grape -sugar,  is  a  crystalline  substance,  and  is 
found  in  honey,  figs,  and  various  other  fruits,  together 
with  another  insoluble  glucose.  It  has  been  found  in 
small  quantity  in  the  liver  and  in  most  of  the  fluids 
of  the  body.  It  is  obtained  by  the  decomposition  of 
salicine,  tannin,  and  other  substances,  which,  for  this 
reason,  have  been  named  glucosides. 

Vegetable  cellulose,  the  envelope  of  many  inverte- 
brates (chitin  and  tunicin)  and  the  glycogenous  princi- 
ple of  the  liver  furnish  glucose  on  treatment  with 
dilute  acids. 

It  is  manufactured  on  a  large  scale  by  the  action  of 
starch  upon  dilute  sulphuric  acid.  Water  containing 
four  to  eight  per  cent,  of  sulphuric  acid  is  placed  in 
vats  and  heated  to  boiling  by  means  of  superheated 
steam.  Before  the  water  boils,  starch  mixed  with 
water  is  added,  and  ebullition  maintained  as  long  as  a 
small  quantity  of  the  mixture  gives  a  blue  reaction 
with  iodine.  The  sulphuric  acid  is  not  changed  during 
this  transformation. 

It  is  then  saturated  with  chalk  and  the  liquid  allowed 
to  become  clear.  It  is  decolored  by  passing  through 


GLUCOSES.  185 

iilters  containing  animal  charcoal  and  evaporated  to  a 
density  of  41°  Baume.  The  glucose  crystallizes  in 
compact  masses.  Often  the  liquid  is  evaporated  to 
only  3°  B.,  when  a  syrup  is  obtained  known  as  starch 
syrup.  Honey  treated  with  cold  concentrated  alcohol, 
also  furnishes  glucose.  The  crystals  of  glucose  are 
small,  opaque,  and  ill  defined. 

They  are  represented  by  the  formula  C6H12O6,2H2O, 
but  they  may  be  obtained  having  the  composition 
C6H12O6  by  precipitating  the  glucose  in  boiling  concen- 
trated alcohol.  The  water  may  also  be  driven  oft'  by 
heating  the  glucose  to  about  100°. 

Glucose  is  soluble  in  a  little  more  than  its  own 
weight  of  water.  Weak  alcohol  dissolves  it  readily. 
It  is  slightly  soluble  in  cold  concentrated  alcohol. 

Its  solutions  turn  the  plane  of  polarization  to  the 
right.  This  rotatory  power  is  feeble  in  the  cold. 

Glucose,  heated  to  about  170°,  acts  in  the  same  man- 
ner as  mannite.  Gelis  has  demonstrated  that  it  loses 
ft  molecule  of  water;  the  body  formed  C6Hi0O5,  is 
called  glucosane,  CgH^Og^CeH^Og  +  HaO.  It  re- 
produces glucose  on  being  boiled  with  acidulated 
water.  If  glucose  is  boiled  with  dilute  nitric  acid, 
saccharic  and  oxalic  acids  are  formed.  Fuming  nitric 
acid  forms  with  glucose  a  very  explosive  compound. 

Hydrochloric  acid  turns  it  brown.  With  dilute  sul- 
phuric acid  it  furnishes  a  double  acid  (sulphoglucio 
acid]',  with  strong  sulphuric  acid,  carbon.  Glucose 
oxydized  with  care,  furnishes  saccharic  acid. 

Heated  to  100°  with  butyric,  or  various  other  acids, 


1  86  ORGANIC    CHEMISTRY. 

it  loses  water,  and  the  glucosane  formed  reacts  upon 
the  acid,  forming  an  ether,  saccharide,  or  dibutyric 
glucosane, 

(C6H6)         j  Q 
(C4H70)H2  \  ^ 

This  body,  as  well  as  other  saccharifies,  are  decom- 
posed under  the  action  of  boiling  acidulated  water, 
into  an  acid  and  glucose. 

Glucose  combines,  with  sodium  chloride,  forming 
several  crystalline  compounds;  it  also  forms  unstable 
compounds  with  the  metallic  bases, 

CaC6H1006 

O    etc. 


Peligot  has  shown  that  the  solutions  of  these  glucos- 
ates  are  gradually  changed  into  salts  of  a  special  acid 
called  glucic  acid,  whose  formula  is 


Cupric  acetate  boiled  with  glucose  is  reduced  to  the 
state  of  suboxide. 

This  action,  which  is  very  slow  with  salts  of  copper 
with  inorganic  acids,  becomes  rapid  and  complete  in 
presence  of  alkalies.  On  adding  glucose  to  a  solution 
of  copper  sulphate,  this  salt  is  not  precipitated  by 
potassa.  If,  however,  the  liquid  is  heated,  it  deposits 
cuprous  oxide.  (Trommer's  test.)  This  reaction  is 
more  delicate  with  copper  salts,  whose  acids  are 


GALACTOSE.  187 

organic.  A  mixture  is  used  of  copper  sulphate, 
Rochelle  salt  and  soda  (Fehling),  or  a  solution  of 
copper  tartrate  in  potassic  hydrate.  (Barreswil.) 

Prof.  W.  S.  Haines  has  found  in  glycerine  a  very 
desirable  substitute  for  the  tartrate  in  Fehling' s  test. 
The  proportions  employed  by  him  for  qualitative  ex- 
aminations are:  cupric  sulphate,  30  grains;  potassic 
hydrate,  1£  drachms;  pure  glycerine,  2  fluid  drachms; 
distilled  water,  6  ounces. 

LEVTJLOSE,    C6H12O6. 

This  name  is  given  to  a  variety  of  glucose,  which  is 
found  in  many  fruits.  It  may  be  obtained  by  boil- 
ing inulin  with  water,  or,  better,  it  can  be  prepared 
from  cane  sugar  by  the  action  of  dilute  acids.  It 
differs  from  the  other  sugars  in  that  its  rotary  power 
diminishes  on  heating. 

GALACTOSE, 

C6H12O6. 

This  body  is  produced  by  boiling,  for  two  or  three 
hours,  sugar  of  milk  with  water  acidulated  with 
sulphuric  acid.  It  is  soluble  in  water  and  insoluble  in 
alcohol;  nitric  acid  transforms  it  into  mucic  acid. 

INOSra,  IMDSITE  OK  MUSCLE  SUGAR. 

C6H12O6  +  2H2O. 
This  substance  is  found  in  many  animal  organs,  and 


188  ORGANIC     CHEMISTRY. 

is  the  chief  constituent  of  the  liquid  which  impreg- 
nates the  muscles. 

It  may  be  prepared  by  first  extracting  the  creatin 
from  the  muscles,  then  separating  the  inosic  acid  with 
baryta.  To  the  liquid  is  then  added  a  quantity  of 
sulphuric  acid  sufficient  to  precipitate  the  whole  of  the 
baryta  and  the  liquid  treated  with  ether,  which  dis- 
solves the  foreign  substances. 

The  aqueous  solution  is  removed  and  alcohol  added 
to  it  until  a  precipitate  is  formed.  Crystals  of  potas- 
sium sulphate  first  separate  out,  then  beautiful  crystals 
of  inosite.  This  substance  has  a  sweet  taste.  At  a 
temperature  of  100°  it  loses  two  molecules  of  water. 
It  dissolves  in  one-sixth  of  its  weight  of  water  while  it 
is  insoluble  in  ether  and  strong  alcohol. 

Inosite  is  without  action  upon  polarized  light.  It 
is  not  converted  into  glucose  by  the  action  of  dilute 
acids,  and  does  not  reduce  copper  salts.  Mixed  with 
milk  and  chalk  it  undergoes  lactic  fermentation. 
(Page  122.) 


SACCHAROSES.  189 


SACCHAROSES. 
ORDINARY  SUGAR, 


This  body  exists  in  a  large  number  of  plants, 
though  it  is  almost  exclusively  extracted  from  the 
sugar-cane  and  beet-root. 

The  sugar-cane,  Arundo  saccharifera,  contains  17 
to  20  per  cent,  of  sugar.  To  extract,  the  juice  of  the 
cane  is  first  obtained  by  expressing.  This  juice  repre- 
sents 60  to  65  per  cent,  of  the  total  weight  of  the  cane, 
and  would  alter  rapidly  in  the  air  if  care  were  not 
taken  to  bring  it  rapidly  to  a  temperature  of  70°,  and 
adding  a  quantity  of  lime.  The  juice  soon  becomes 
covered  with  foam  and  deposits  different  albuminoid 
and  other  matters,  which  are  precipitated  by  the  lime. 
It  is  decanted  into  pans  and  rapidly  evaporated.  The 
sugar  crystallizes  out,  and  the  mother  liquor  is  evapo- 
rated as  long  as  it  furnishes  crystals.  The  thick  liquid 
which  remains  is  molasses.  The  sugar  thus  obtained 
is  brown  sugar,  and  is  subsequently  refined. 

The  beet-root  most  rich  in  sugar  is  that  of  Silesia. 
It  contains  about  10  per  cent,  of  sugar.  Sugar  crys- 
tallizes in  clinorhombic  prisms.  They  may  be  readily 
obtained  by  slowly  evaporating  a  solution  of  sugar. 


190  ORGANIC    CHEMISTRY. 

The  crystals  of  ordinary  sugar  are  very  small,  as  the 
syrup  is  made  to  crystallize  quite  rapidly.  Cold  water 
dissolves  three  times  its  weight  of  sugar;  hot  water 
dissolves  it  in  all  proportions,  forming  a  syrupy  liquid. 
It  is  not  dissolved  by  cold  alcohol  or  ether.  Dilute 
alcohol  dissolves  it  in  proportion  as  it  is  more  or  less 
aqueous.  Its  solutions  are  dextrogyrate.  Sugar  melts 
at  about  180°,  and  yields  a  liquid  which  solidities 
to  a  vitreous,  amorphous  mass,  called  barley  sugar, 
which  becomes  opaque  and  crystalline  after  some  time. 

If  sugar  is  heated  a  little  above  this  point,  it  is 
transformed  into  glucose  and  levulosane. 

CiaH^On^CeH^Og  +  C6H10O5. 

Levulosane. 

At  about  190°  sugar  loses  water,  becomes  brown, 
and  finally  furnishes  a  substance  which  is  commonly 
known  as  caramel.  According  to  Grelis  three  pro- 
ducts of  dehydration  are  formed,  caramelane,  carn- 
melene  and  earameline.  At  a  temperature  of  230° 
to  250°  sugar  is  decomposed  into  carbon  monoxide, 
carbon  dioxide,  carbohydrides  and  different  empyreu- 
matic  products.  Sugar  is  transformed  slowly  in  the 
cold,  and  rapidly  at  80°,  in  contact  with  dilute  acids 
into  inverted  sugar,  which  is  thus  called  on  account 
of  its  inverted  action  upon  polarized  light.  On  pro- 
longed ebullition  the  solution  is  rendered  brown  and 
ulmic  products  are  formed.  Sugar  reacts  with  baryta 
water  and  lime  water,  forming  different  compounds 
called  sucrates  or  saccharates. 


SUGAR    OF    MILK.  191 

The  solutions  of  these  sucrates  are  decomposed  by 
carbon  dioxide  :  sugar  is  reformed.  Rousseau  makes 
use  of  this  fact  in  the  manufacture  of  sugar  on  a  very 
large  scale. 

Sugar  does  not  ferment  immediately  in  contact 
with  beer  yeast. 

SUGAK   OF    MILK,    LACTIN    OK    LACTOSE. 

CiaH^Oj!  +  H2O. 

It  is  obtained  from  milk,  by  precipitating  the  casein 
with  a  few  drops  of  dilute  sulphuric  acid,  filtering 
and  evaporating  the  liquid. 

Crystals  are  deposited,  which  are  purified  by  re- 
dissolving  and  treating  with  animal  charcoal. 

In  Switzerland  large  quantities  of  sugar  of  milk 
are  made  by  evaporating  the  whey  which  remains 
after  the  separation  of  the  cheese. 

The  crystals  of  this  body  are  rhombic  prisms. 
This  sugar  is  insoluble  in  ether  and  alcohol,  and 
requires  2  parts  of  boiling  and  6  parts  of  cold  water 
for  its  solution. 

Its  solutions  are  dextrogyrate.  At  a  temperature 
of  about  140°  it  loses  H2O,  and  becomes  brown  at  160° 
to  180°. 

In  presence  of  sour  milk  and  chalk  it  undergoes 
lactic  fermentation. 

Sugar  of  milk  is  extensively  used  in  homoeopathic 
pharmacy;  also  in  the  pepsin  of  commerce,  and  in  sac- 
charated  extracts. 


192  ORGANIC     CHEMISTRY. 

Reichardt  has  obtained  from  gum  arable  a  sugar 
•distinct  from  ordinary  sugar,  a  body  though  having 
the  same  formula.  He  names  it para-arabin. 

HONEY. 

Honey  is  produced  by  the  domestic  bee  (Apis  mel- 
lifica),  an  insect  of  the  order  Hyinenoptera. 

It  is  separated  from  the  wax  by  exposing  the  honey- 
comb to  the  sun,  on  wire  nets;  very  pure  honey  is 
thus  obtained. 

The  mass  which  remains  is  expressed,  and  this  prod- 
uct is  a  second  quality  of  honey,  more  colored  and 
of  a  less  agreeable  taste  and  odor  than  the  first.  The 
comb  is  then  heated  with  water  to  remove  the  remain- 
der of  the  honey.  The  wax  thus  isolated  is  melted 
and  run  into  moulds.  Honey  owes  its  sweet  taste  to 
several  sugars.  There  is  found  in  it  a  dextroyrgate, 
crystallizable  glucose,  and  on  removing  this  sugar 
there  remains  a  viscid  uncry  stall  izable  liquid,  which 
contains  levulose.  In  addition  to  these,  small  quan- 
tities of  ordinary  sugar  have  also  been  found  in 
honey. 

GLUOO8IDES. 

This  name  is  given  to  certain  bodies  which  have 
the  property  of  forming  various  products  by  combin- 
ing with  water,  among  which  is  glucose,  or  some  other 
saccharine  matter. 

This  change  is  •produced  by  the  action  of  acids, 
bases,  or  by  the  action  of  ferments.  We  cite  the  fol- 
lowing, but  shall  only  study  the  most  important: 


GLUCOSIDE8.  193 

Salicin,  C13H18O7,  extracted  from  the  bark  of  the 
Willow. 

Amygdalin,  C^H^NOn,  extracted  from  the  Bitter 
Almond,  Amygdalus  communis. 

Orcin,  C7H8O2,  extracted  from  various  Lichens. 

Tannin,  C^H^O^,  extracted  from  the  Oak. 

Phlorizin,  C^H^O^,  extracted  from  the  Apple,  Pear, 
or  Cherry  tree. 

Populin,  CaoH^Og,  extracted  from  Aspen  leaves. 

Arbutin,  C13H16O7,  extracted  from  the  leaves  of  the 
Uva-Ursa. 

Convolvulin,  C^HsoO^,  extracted  from  the  Convol- 
vulus orizabensis  and  sehiedeanus. 

Jalappin,  C^HggOjg,  extracted  from  Convolvulus 
orizabensis  and  scammonia. 

Saponin,  a  white  amorphous  powder  whose  solution 
is  very  frothy  and  of  which  the  powder  is  very  sternu- 
tatory. 

Daphnin,  C^H^O^,  the  crystalline  matter  extracted 
from  the  bark  of  the  Ash  {Fraxinus  excelsior). 

Cyclamin  C^H^O^,  extracted  from  the  tubercles  of 
the  Cyclamen  europium. 

Quinovin,  CajH^Og,  a  resinous,  bitter  matter,  solu- 
ble in  alcohol,  existing  in  the  bark  of  the  Quina  nova 
and  other  cinchonas. 

Solanin,  C43H71N016.  This  has  already  been  studied, 
(page  165). 

Esculin,  CsoH^Oig,  extracted  from  the  bark  of  the 
Horse  Chestnut. 

Quercitrin,  C29H30O17,  from  the  bark  of  the  yellow 
oak  (Quercus  tinctorial. 


194  ORGANIC    CHEMISTRY. 

Coniferin,  C^HooOs,  from  the  Larix  europaea,,  etc. 
Vanillin,  from  the  Vanilla  bean,  and  recently  ob- 
tained artificially  (60-74^-608). 

SALICIN,    Ci3lli8O7  -h  H2O. 

This  body  crystallizes  in  white  needles,  fusible  at 
120°,  insoluble  in  ether,  soluble  in  alcohol  and  water. 
These  solutions  are  levogyrate  and  very  bitter.  It  is 
used  as  a  febrifuge,  but  is  of  little  value  in  well  de- 
nned intermittent  fevers. 

It  has  as  a  distinguishing  chemical  character,  the 
property  of  becoming  red  with  sulphuric  acid. 

Under  the  action  of  dilute  sulphuric,  or  hydro. 
chloric  acid,  or  even  with  emulsin,  salicin  is  decom- 
posed. With  the  latter  the  reaction  is: 


C13II,807  +  H,0=C6H13()«  +  C7H80, 

Glucose.        Saligenin. 

In  contact  with  cold  nitric  acid  it  loses  hydrogen, 
and  a  body  is  formed  called  lielicin,  C13H16O7. 

When  treated  with  oxydizing  agents,  it  gives  oif  an 
odor  which  is  identical  with  that  of  the  essence  of 
meadow  sweet  (Spirea  ulmaria). 

This  body  is  produced  especially  when  salicin  is 
treated  with  a  mixture  of  sulphuric  acid  and  potas- 
sium bichromate,  and  is  also  known  by  the  name  of 
hydride  ofsalicyl. 

Its  formula  is  identical  with  that  of  benzoic  acid, 
(^Ilf,  Oo,  bur,  it  has  not  the  properties  of  this  acid. 


SALICIN.  195 

It  is  an  aromatic  liquid,  boiling  at  196°,  and  has  the 
property  of  oxydizing  spontaneously,  giving  rise  to 
an  acid  called  salicylic  acid,  C7H6O3. 

Salicin,  treated  with  fused  potassa,  furnishes  potas- 
sium oxalate  and  salicylate.  Cahours  has  shown  that 
essence  of  Gaultheria  procumbem,  a  heath  of  New 
Jersey,  contains,  besides,  an  isomer  of  the  essence 
of  turpentine,  a  sweet-scented  liquid,  boiling  at  220°, 
which  is  salicylic  methyl  ether,  and  is  re-converted, 
in  contact  with  alkalies,  into  methyl  alcohol  and  sali- 
cylic acid  :  it  may  be  produced  artificially  by  treating 
wood  spirit  with  a  mixture  of  salicylic  and  sulphuric 
acids. 

Salicylic  or  oxybenzoic  acid  has  been  lately  pro- 
duced by  Kolbe  (56  -'74  -22),  by  a  remarkable  syn- 
thesis in  acting  on  carbolate  of  sodium  with  CQ2. 

2C6H50]Sra  +  CO2=C6H6O  +  C.HA 


Sodium  phenol.  Sodium  salicylate  of  sodium. 

It  has  now  come  to  be  a  very  important  article  in 
pharmacy  and  in  the  arts,  on  account  of  its  efficiency 
as  an  antiseptic,  equaling  or  surpassing  carbolic  acid 
(phenol),  yet  without  the  unpleasant  odor  of  the  latter 
body,  or  its  toxical  qualities.  As  of  considerable  im- 
portance theoretically,  it  should  be  stated  that  Herr- 
mann has  very  lately  (60- April,  '77)  obtained  salicylic 
acid  by  the  action  of  sodium  upon  succinic  ether. 


196  OKGANIC    CHEMISTRY. 


TANNINS. 

This  is  the  name  given  to  different  principles  exist- 
ing in  plants,  which  are  characterized  by  the  following 
properties: 

1st.  They  give,  with  ferric  salts,  a  black  coloration 
approaching  blue  or  green. 

2d.  They  precipitate  solutions  of  albuminoid  sub" 
stances,  particularly  those  of  gelatine. 

The  principal  ones  are: 

Tannin  of  oak,  C^ILoO^. 

"         "  cachou  (catechin  or  catechic  acid). 

"  quinquinia  (quinotannic  acid). 
"         "  coffee  (caffetannic  acid). 

"  fustic  (morintannic  acid). 

Oak  tannin  is  best  prepared  from  gall-nuts  which 
contain  much  more  than  does  the  bark.  The  nuts 
are  pulverized  and  submitted  to  the  action  of  commer- 
cial sulphuric  ether,  which  is  made  aqueous.  This 
ether  may  be  replaced  with  advantage  by  a  mixture  of 
600  grams  of  pure  ether,  30  grams  of  90  per  cent, 
alcohol,  and  10  grams  of  distilled  water  for  every 
100  grams  of  gall-nuts.  After  twenty-four  hours  the 
apparatus  contains  two  layers  of  liquid;  the  upper  one 
is  ether,  containing  but  little  tannin,  while  the  lower 
one  is  a  very  strong  aqueous  solution  of  tannin. 

The  lower  layer  is  removed  and  evaporated  in  an 


TANNIN.  197 

oven  on  shallow  plates.  There  remains  an  amorphous 
spongy  substance,  very  soluble  in  water,  less  soluble 
in  alcohol,  and  almost  insoluble  in  ether.  This  residue 
is  very  astringent  and  slightly  acid. 

Solutions  of  tannin  give  a  white  precipitate  with 
tartar  emetic. 

It  precipitates  solutions  of  the  alkaloids,  and  coagu- 
lates blood. 

With  solutions  of  gelatin  it  gives  a  voluminous  pre- 
cipitate, soluble  on  heating  in  an  excess  of  gelatin. 

Tannin  forms,  with  fresh  hide,  an  imputrescible  com- 
pound, which  is  leather.  The  art  of  tanning  is  based 
on  the  action  of  oak-bark  tannin  on  hides  from  which 
the  hair  has  been  removed,  usually  by  lime. 

GALLIC  ACID.  In  solution,  tannin  is  gradually  de- 
composed, the  liquid  becoming  covered  with  mould. 

Carbon  dioxide  is  disengaged  and  an  acid,  called 
gallic  acid,  is  formed. 

This  transformation  does  not  take  place  if  all  air  is 
•excluded;  and  the  air  alone  is  not  sufficient.  It  requires 
the  presence  of  a  mycelium  of  a  mucedin  conveyed  to 
the  liquid  either  by  the  air  or  in  some  other  manner. 

This  transformation  is,  like  alcoholic  fermentation, 
a,  phenomenon  correlative  with  the  development  and 
growth  of  an  organism.  On  boiling  tannin  with  water 

o  o  o 

acidulated  with  hydrochloric  or  sulphuric  acid,  it  is 
decomposed  into  glucose  and  gallic  acid: 

CAA:  +  4H20=3(C7H  A)  +  C6HrA- 

Gallic  acid.          Glucose. 


198  ORGANIC     CHEMISTRY. 

Gallic  acid  is  deposited  as  the  liquid  becomes  cooL 
It  is  purified  by  redissolving  and  treating  with  animal 
charcoal,  and  recrjstallizing. 

O  TT  O  ) 

Gallic  acid,  C7H6O5—   TT  |r   [  O4,  crystallizes  in  silky 

needles,  soluble  in  three  parts  of  boiling  water,  bnt 
little  soluble  in  cold  water.  This  solution,  on  standing 
in  the  air,  becomes  altered  after  a  long  time,  carbon, 
dioxide  is  disengaged  and  the  solution  turns  brown : 
alkalies  accelerate  this  change. 

Gallic  acid  produces  a  blue  color  with  ferric  salts, 
and  precipitates  tartar  emetic,  but  does  not  precipitate 
gelatin  when  pure,  nor  the  alkaloids. 

Mixed  with  pumice-stone  and  heated  to  210°  it  pro- 
duces a  beautiful  sublimate  otpyrogallic  acid,  carbon 
dioxide  being  liberated  at  the  same  time. 

C7HtiOr=Cc,H603  +  C02. 

This  body  occurs  in  colorless,  acicular  crystals, 
fusible  at  about  115°,  and  soluble  in  2.5  parts  of 
water.  Its  solution  absorbs  oxygen  from  the  air,  in 
presence  of  alkalies,  and  becomes  quite  brown. 

It  reduces  gold  and  silver  salts,  and  forms  unstable 
compounds  with  certain  acids.  It  may  properly  be 
placed  among  the  phenols.  This  body  is  employed 
in  photography,  and  in  the  laboratory.  Mercadante 
(47-' 74-484)  finds  that  gallic  acid  is  injurious  to 
vegetation,  inasmuch  as  it  combines  with  the  mineral 
food  of  the  plant  rendering  it  insoluble. 

Grimaux  was  the  first  to  consider  gallic  acid  as 
tetratomic  and  monobasic  (77-620). 


VEGETABLE    CHEMISTKY.  199 


VEGETABLE  CHEMISTRY. 

At  the  moment  when  the  radicle  of  a  plant  appears 
above  the  ground,  its  vital  phenomena  undergo  a 
marked  change. 

The  plant  decomposes  carbon  dioxide,  water  and 
certain  nitrogenous  compounds  furnished  by  the  soil, 
and  grows  by  retaining  carbon,  hydrogen,  nitrogen  and 
a  little  oxygen,  and  returns  to  the  air  the  greater  part 
of  the  oxygen  derived  from  the  carbon  dioxide,  water 
and  nitrogenous  compounds. 

Bonnet  observed,  in  the  last  century,  that  leaves, 
exposed  to  the  sun  in  areated  water,  disengage  a  gas, 
which  Priestly  showed  is  oxygen.  Sennebier  discovered 
that  this  oxygen  is  derived  from  carbon  dioxide.  De 
Saussure  verified  these  facts,  and  demonstrated  that 
this  decomposition  of  carbon  dioxide  does  not  take 
place  in  the  dark,  and  that  the  green  portions  of  the 
plant  alone  are  capable  of  effecting  the  change. 

J.  Belluci  (9-78-362)  has  lately  shown  that,  con- 
trary to  former  belief,  none  of  the  oxygen  exhaled  by 
plants  is  in  the  form  of  ozone. 

EXPERIMENT. — Place  a  few  leaves  in  a  flask  half  full 
of  water  containing  carbon  dioxide,  usoda  water,"  invert 
the  flask  over  a  glass  of  water,  and  expose  it  to  the  sun- 
light, after  having  covered  it,  if  the  sun  is  very  hot, 
with  a  sheet  of  transparent  paper;  minute  bubbles  will 


200  ORGANIC    CHEMISTRY. 

soon  be  seen  to  form  on  the  leaves,  as  small  as  the  point 
of  a  pin,  will  increase  in  size,  unite  and  mount  to  the 
upper  part  of  the  flask.  Transfer  this  gas  to  a  test- 
tube,  and,  on  examination,  it  will  be  found  to  be  oxy- 
gen. Substitute  for  this  flask  an  opaque  vessel,  or  per- 
form the  experiment  in  the  dark,  and  the  carbon  diox- 
ide will  not  be  altered  in  the  least. 

Where  do  the  plants  find  this  carbon  dioxide  ? 
Chiefly  in  the  air.  Boussingault,  in  order  to  demon- 
strate this,  placed  under  a  bell-glass  some  peas  planted 
in  calcined  sand;  he  watered  them  with  pure  distilled 
water,  and  passed  air  into  the  glass;  the  peas  grew, 
flowered  and  bore  fruit. 

Now  the  substance  of  these  peas  contained  carbon 
hydrogen  and  nitrogen,  in  much  greater  quantity 
than  the  seed  from  which  they  grew,  consequently 
these  constituents  were  taken  from  the  air  and  water. 

If,  however,  the  air  be  made  to  pass  through  an 
alkaline  solution  before  escaping  from  the  vessel,  no 
carbon  dioxide  is  absorbed,  which  also  proves  that  the 
carbon  dioxide  existing  in  the  air  has  been  removed 
by  the  plant.  The  plant  takes  up,  in  the  same  man- 
ner, carbon  dioxide  from  the  water  which  passes  from 
the  soil  into  its  roots. 

Plants  are  also  capable  of  decomposing  water,  in 
fact,  Collin  and  W.  Edwards  have  proved  that  the  sub- 
merged stems  of  the  Polygonum  tinctorium  and  cer- 
tain mushrooms,  exhale  hydrogen. 

On  the  other  hand,  Payen  has  proved  that  the  hy- 
drogen exceeds  the  oxygen  in  the  woody  parts  of 


VEGETABLE    CHEMISTRY.  20 L 

plants,  and,  indeed,  many  substances  produced  bj 
plants,  as  oils  and  resins,  are  very  rich  in  hydrogen. 
In  short,  the  oxygen  contained  in  the  plant  would  not 
be  sufficient  to  oxydize  or  transform  into  water  the 
whole  of  the  hydrogen  it  contains,  consequently  it 
must  be  admitted  that  water  is  decomposed  by  plants. 
The  conditions  under  which  this  change  takes  place 
liave  not  as  yet  been  determined. 

The  experiment  of  Boussingault  proves,  as  Ingen- 
housz  has  claimed,  that  the  air  furnishes  the  plant  with 
nitrogen;  but  where  does  this  nitrogen  come  from?  Is 
it  taken  by  the  plant  from  the  free  nitrogen  of  the  atmos- 
phere? or  is  it  derived  from  the  nitric  or  nitrous  acids^ 
or  from  the  ammonia  contained  in  the  atmosphere,  or, 
in  one  word,  from  the  nitrogenous  compounds  existing 
in  the  air? 

Boussinganlt  has  shown  that  while  certain  families 
of  plants,  principally  the  common  vegetables,  derive 
from  the  air  a  large  quantity  of  nitrogen,  even  taking 
up  free  nitrogen,  others,  the  cereals  for  instance,  derive 
nitrogen  chiefly  from  the  soil;  for,  on  causing  clover 
and  wheat  to  grow  in  calcined  sand  in  presence  of  air 
deprived  of  its  nitrogenous  compounds,  and  distilled 
water,  he  observed  that  the  clover  took  up  carbon,  hy- 
drogen, water  and  nitrogen,  while  it  appears  that  the 
wheat  obtained  from  the  air  carbon  and  water  only. 

Nitrogen,  which  is  present  in  the  air  in  the  form  of 
ammonium  nitrate,  is  absorbed  by  all  plants.  Direct 
experiments  have  shown  that  the  salts  of  ammonium, 
especially  ammonium  nitrate,  constitute  an  excellent 


202  ORGANIC     CHEMISTRY. 

compost,  and  consequently  this  nitrate  can  lose  its  oxy- 
gen, or  become  reduced  in  the  plant. 

Now,  it  is  known  that  urea  and  animal  excreta  are 
transformed  into  ammoniacal  compounds  on  exposure 
to  the  air;  therefore,  in  order  to  obtain  a  good  cropr 
even  with  plants  which  take  up  the  nitrogen  of  the  air, 
it  is  necessary  to  employ  manures  which  furnish  not 
only  easily  assimilated  nitrogen,  but  those  which,  be- 
sides, furnish  the  plant  with  soluble  organic  com- 
pounds and  the  mineral  substances  necessary  for  its 
development  and  growth.  Of  these  latter  there  is  re- 
quired for  the  plant,  potassium  and  calcium  chlorides, 
sulphates,  phosphates,  etc. 

With  the  four  elements,  carbon,  hydrogen,  nitrogen, 
and  oxygen,  nature  forms  an  infinite  variety  of  com- 
pounds by  mysterious  methods,  to  which  we  have  not, 
as  yet,  the  key,  but  of  which  synthetical  research  gives 
us  some  idea.  Thus,  with  carbon  dioxide  and  water, 
Berthelot  produces  formic  acid;  with  formic  acid  he 
obtains  alcohol,  and  subsequently  acetic  acid.  Pasteur 
also  has  shown  that  glycerine,  one  of  the  principles  of 
fat,  is  produced  in  the  process  of  fermentation  and 
that  a  complex  acid,succinic  acid,  is  also  formed  under 
the  same  circumstances.  However,  we  are  far  from 
knowing  how  to  produce  those  substances  which  nature 
forms  at  ordinary  temperatures,  and  with  only  four 
elements.  What  wondrous  chemistry  is  that  of  the 
plant,  fitted  by  an  all-wise  Creator  to  elaborate  with 
puch  simple  materials,  the  beauteous  violet,  the  fragrant 
rose,  or  the  luscious  fruit ! 


VEGETABLE    CHEMISTRY.  203 

By  combining  six  atoms  of  carbon  with  five  atoms 
of  water,  nature  forms  either  the  woody  principle,  cel- 
lulose^ or  the  essential  constituent  of  the  potato,  starch. 
By  uniting  ten  atoms  of  carbon  with  sixteen  atoms  of 
hydrogen,  she  produces,  in  the  orange  and  in  the  piiie, 
two  essences  or  oils  very  different  in  character.  By 
associating  the  four  organic  elements  she  forms  the 
most  different  substances,  the  nourishing  cereal  as  well 
as  the  most  deadly  strychnia;  and  often  products  as 
unlike  as  these  are  found  side  by  side  in  the  same 
plant. 

Thus  the  plant  is  a  structure  which  decomposes  car- 
bon dioxide,  water,  and  compounds  of  nitrogen;  which 
forms  its  substance  out  of  carbon,  hydrogen,  nitrogen, 
and  a  part  of  the  oxygen  of  these  compounds,  and 
which  exhales  oxygen.  Hence,  chemicalhT,  it  would  be 
proper  to  call  the  plant  a  reducing  apparatus. 

We  should  add  that  the  flowers  and  portions  of 
plants  not  green,  also  the  buds  in  developing,  produce 
an  exhalation  of  carbon  dioxide,  and  that  during  £er- 

O      o 

mination,  and  especially  during  the  time  of  flowering, 
a  sensible  amount  of  heat  is  disengaged.  As  a  result 
of  this  elevation  of  temperature,  there  is  produced  in 
plants  some  slight  oxydation  or  combustion,  as  in  the 
respiration  of  animals. 

Hence,  we  must  conclude  that  plants  and  animals, 
in  many  circumstances  at  least,  deport  themselves  in 
a  similar  manner. 

Many  experimenters,  and  especially  Dutrochet  and 
Garreau,  go  further,  and  say  that  plants  and  animal 


204  ORGANIC     CHEMISTRY. 

respire  in  an  identical  manner,  and  according  to  their 
theories  all  living  creatures  take  up  oxygen  and  exhale 
carbon  dioxide. 

The  experiments  of  Garreau  especially  deserve  at- 
tention. He  placed  branches,  detached  or  affixed  to 
the  plant,  in  vessels  full  of  air,  and  exposed  them  to  a 
diffused  light.  The  volume  of  the  air  was  known  and 
the  oxygen  absorbed  was  determined  by  a  special  con- 
trivance ;  the  carbon  dioxide  produced  was  removed 
by  placing  in  the  vessel  an  alkaline  solution  of  known 
weight.  Thus  the  variations  of  these  gases  were  care- 
fully studied. 

As  a  result  of  his  experiments  Garreau  claimed  to 
have  established  that  both  in  the  dark  and  in  the 
light,  there  is  an  absorption  of  oxygen  and  an  ex- 
halation of  carbon  dioxide,  but  the  amount  of  car- 
bon dioxide  collected  does  not  represent  the  amount 
really  exhaled,  as  the  greater  part  is  reduced  at  the 
moment  of  liberation.  From  these  facts  it  would 
appear  that  in  all  living  creatures  the  same  phenome- 
non of  respiration  takes  place,  which  consists  in  a 
consumption  of  oxygen  and  an  exhalation  of  carbon 
dioxide. 

This  phenomenon  is  associated  with  another  ;  viz., 
assimilation  or  nutrition.  It  is  here  that  the  differ- 
ence, indeed  a  complete  opposition,  between  the  two 
kingdoms  is  established.  The  plant  grows  by  re- 
ducing, under  the  influence  of  heat  and  sunlight, 
carbon  dioxide,  water  and  nitric  acid,  by  accumulating 
carbon,  hydrogen,  nitrogen  and  by  exhaling  the  greater 


ORGANIZED    SUBSTANCES.  205 

part  of  the  oxygen.  The  animal,  on  the  other  hand, 
forms  its  substance  from  that  of  the  plant,  oxydizing, 
or  consuming,  the  vegetable  products  with  the  oxy- 
gen of  the  air  exhaled  by  the  plants;  it  reduces  the 
complex  products  formed  in  the  vegetable  to  the  state 
of  carbon  dioxide,  water  and  ammonia;  thus  the  ani- 
mals supply  the  plants  with  food,  receiving  in  turn 
nourishment  from  them.  Those  desirous  of  further 
studying  this  and  other  interesting  topics  relating  to 
Vegetable  Chemistry,  will  find  very  valuable  the 
works  of  Prof.  S.  W.  Johnson,  "  How  Crops  Grow," 
and  "How  Crops  Feed";  also  Prof.  John  C.  Draper's 
article  in  Am.  Jour.  Sci.  and  Arts,  Nov.  1872,  entitled 
''Growth  of  Seedling  Plants." 

ORGANIZED    SUBSTANCES. 

Among  the  chemical  substances  of  which  we  have 
spoken  certain  ones  participate  more  in  vital  phe- 
nomena, and  have  more  definite  physical  structure  than 
do  others. 

These  are  designated  as  organized  or  organizable 
substances,  the  term  organic  being  reserved  for  the 
definite  compounds  studied  in  organic  chemistry.  All 
these  substances  play  an  important  part  in  the  veget- 
able kingdom,  forming  the  network  of  vegetable  tis- 
sue, as  cellulose  or  as  starch,  etc. 

CELLULOSE    OR    CELLULIN,    (C6H10O5)n. 

On  examining  a  young  plant  under  the  microscope, 


206  ORGANIC    CHEMISTRY. 

we  observe  that  it  is  built  up  of  little  cells  and  mi- 
nute, diaphanous  ducts  or  vessels  filled  with  sap  and 
air.  The  material  of  which  these  tissues  are  com- 
posed is  called  cellulose.  The  pith  of  the  elder,  cot- 
ton fibre,  and  paper  are  almost  exclusively  composed 
of  this  substance. 

Cellulose  is  a  carbo-hydrate ;  C6H10O5,  is  the 
formula,  ordinarily  given  to  it,  although  a  multiple 
formula  at  least  three  times  as  large/ or  C18HgoOi5  is 
necessary  to  explain  certain  reactions  with  nitric  acid. 

EXPERIMENT.  Pure  cellulose  may  be  obtained  in  the 
following  manner :  cotton,  linen  or  paper  is  treated  with 
dilute  alkaline  solutions,  washed  and  immersed  in  weak 
chlorine  water;  finally  it  is  submitted  to  the  action  of 
various  solvents,  as  water,  alcohol,  ether  and  acetic 
acid  until  nothing  more  is  dissolved. 

This  substance  is  solid,  white  and  insoluble.  It  is 
destroyed  at  a  red  heat,  producing  carbon  and  numer- 
ous carbohydrides,  gaseous  and  liquid,  which  distil 
over.  With  monohydrated  sulphuric  acid  it  produces 
a  colorless,  viscid  liquid,  which  contains,  at  first,  an 
insoluble  substance  having  the  properties  of  starch  and 
yielding  a  blue  color  with  iodine.  If  the  action  of  the 
acid  is  continued,  the  whole  is  dissolved  and  the  same 
products  are  obtained  as  in  the  case  of  starch  when 
brought  in  contact  with  sulphuric  acid,  i.  e.  dextrin 
and  glucose.  To  separate  the  latter  substance,  it  is 
simply  necessary  to  saturate  the  acid  with  chalk  and 
evaporate  the  liquid. 

Concentrated  hydrochloric  acid  produces  the  same 


CELLULOSE.  207 

e&ect.  If  paper  be  immersed  for  an  instant  only  in 
sulphuric  acid,  diluted  with  half  its  volume  of  water, 
and  carefully  washed,  it  acquires  the  toughness  of 
parchment.  Paper  thus  prepared  is  frequently 
employed  in  experiments  on  dialysis ;  it  is  also  much 
used  by  pharmacists  to  cover  the  stoppers  of  bottles. 
It  is  known  in  commerce  as  vegetable  parchment. 

GUN  COTTON  OK  PYROXYLIN. 

Gun  cotton  was  first  made  by  Schoenbein,  in  1846. 

To  prepare  it  cotton  is  plunged  for  two  or  three 
minutes  into  fuming  nitric  acid,  or,  better,  into  a  mix- 
ture of  1  vol.  nitric  acid  (of  a  density  of  1.5),  and  2 
vols.  of  strong  sulphuric  acid;  it  is  then  thoroughly 
washed  and  dried  at  a  low  temperature. 

The  cotton  is  not  changed  in  appearance  other  than 
becoming  -somewhat  wrinkled.  "When  well  prepared 
it  burns  completely,  leaving  no  residue.  The  tem- 
perature at  which  it  takes  lire  varies  from  100°  to  180° 
according  to  the  manner  in  which  it  has  been  pre- 
pared. It  is  cellulose  in  which  from  six  to  nine  atoms 
hydrogen  have  been  replaced  by  an  equivalent  quan- 
tity of  the  monad  radicle  NO^  that,  having  the 
formula  C]8H21O159NO2,  has  the  greatest  explosive 
energy.  Pyroxylin  regenerates  cellulose  in  contact 
with  ferrous  chloride.  If  cellulose  be  considered  a  sort 
of  alcohol,  as  claimed  by  some,  pyroxylin  would  be  a 
nitric  ether  of  this  alcohol. 

Pyroxylin   has  the  advantage   over  gunpowder  of 


208  ORGANIC   CHEMISTRY. 

being  more  easily  prepared,  and  of  remaining  unaf- 
fected by  moisture,  but  its  cost  is  relatively  greater, 
and  its  shattering  power  renders  its  employment 
dangerous.  * 

The  term  collodion  (from  xohXa,  glue)  is  given  to  a 
preparation  obtained  by  dissolved  gun-cotton  in  a 
mixture  of  1  part  of  alcohol  and  4  parts  of  ether. 

Chas.  H.  Mitchell  has  made  (52-74-235)  a  number 
of  experiments,  with  the  view  of  ascertaining  the  rela- 
tive proportions  of  cotton  and  acid,  together  with  the 
proper  time  of  maceration  necessary  to  produce  a 
cotton  which  should  combine  the  largest  yield  with 
the  highest  explosive  power  and  solubility. 

The  following  formula  was  at  length  adopted: 

Raw  cotton,  .  2  parts. 

Potassium  carbonate,  1      " 

Distilled  water,  100      « 

Boil  for  several  hours,  adding  water  to  keep  up  the 
measure ;  then  wash  until  free  from  any  alkali,  and 
dry.  Then  take  of — 

Purified  cotton,  7  oz.  av. 

Nitrous  acid  (nitric,  saturated  with  nitrous  acid), 
s.  g.  1.42,  4  pints. 

Sulphuric  acid,  s.  g.  1.84,  -4      " 

Mix  the  acids  in  a  stone  jar  capable  of  holding  2  gals., 
and  when  cooled  to  about  80°  Fahr.,  immerse  the  cot- 
ton in  small  portions  at  a  time ;  cover  the  jar  and 
allow  to  stand  4  days  in  a  moderately  cool  place  (temp. 
50°  to  70°  Fahr.)  then  wash  the  cotton  in  small  por- 


CELLULOSE.  209 

tions,  in  hot  water,  to  remove  the  principal  part  of  the 
acid;  pack  in  a  conical  glass  percolator,  and  pour  on 
distilled  water  until  the  washings  are  not  affected  by 
solution  of  barium  chloride. 

Collodion,  on  spontaneously  evaporating,  forms  a 
transparent  and  impermeable  membraneous  coating, 
and  is  much  employed  in  photography,  also  somewhat 
in  surgery. 

Cellulose  is  attacked  by  chlorine;  the  use  of  solu- 
tions of  chloride  of  lime,  and  of  chlorine,  in  large 
quantities  in  washing,  or  bleaching,  will  cause  a  rapid 
deterioration  of  linen  or  cotton  goods. 

Schweizer  has  shown  that  cotton,  paper,  etc.,  is 
very  easily  dissolved  by  an  ammoniacal  solution  of 
copper.  Attempts  by  the  author  to  employ  this 
sohition  for  a  '"water-proof"  coating  of  fabrics,  as  has 
been  suggested,  failed  to  yield  a  satisfactory  result,  on 
account  of  the  liability  of  the  coating  to  crack  and 
peel  off. 

Peligot  has  found  in  the  skin  of  silk  worms,  and 
Schmidt  has  discovered  in  the  envelopes  of  the 
Tunicates,  a  substance,  tunicine,  which  has  the  com- 
position and  properties  of  cellulose. 

Linen,  hemp,  cotton,  wood  and  paper  are  all  essen- 
tially cellulose. 


210  ORGANIC     CHEMISTRY. 


AMYLACEOUS  SUBSTANCES. 

These  substances  are  almost  universally  present  in 
plants;  particularly  that  known  as  starch  orfecula. 

The  potato  yields  about  20  per  cent,  of  starch.  In 
order  to  obtain  it,  this  root  is  grated  and  the  pulp 
placed  upon  sieves,  arranged  one  above  the  other,  and 
through  which  a  stream  of  water  flows. 

The  grains  of  starch  being  extremely  minute  pass 
through  the  meshes  of  the  sieve,  while  the  walls  of  the 
cells  remain  behind.  The  starch  is  washed,  drained, 
and  dried,  first  at  ordinary  temperature,  afterwards  by 
the  application  of  a  moderate  heat. 

STARCH.  a?(C6Hi0O5)  probably  C^H^O^.  Flour 
contains,  besides  starch,  nitrogenous  substances,  de- 
nominated gluten;  this  gluten  is  capable  of  ferment- 
ing, whereupon  it  becomes  soluble,  while  the  starch 
remains  unaltered  and  insoluble.  Under  these  con- 
ditions the  gluten  gradually  dissolves,  disengaging 
ammoniacal  compounds,  hydrogen  sulphide  and  other 
products  of  putrefaction. 

At  the  end  of  twenty  or  thirty  days,  the  gluten 
having  become  dissolved,  the  liquid  is  removed,  and 
the  starch,  washed  and  dried,  shrinks  into  columnar 
fragments,  which  are  readily  pulverized  by  gentle 
pressure. 


STARCH.  211 

A  more  modern  method  is  that  employed  in  France, 
which  is  essentially  the  same  as  the  process  cited  above, 
as  that  used  in  making  potato  starch  here.  The  water 
carries  away  the  starch  while  the  gluten  remains  be- 
hind in  the  form  of  an  elastic  mass,  which  is  also  util- 
ized. For  this  purpose  it  is  incorporated  with  flour 
poor  in  gluten,  to  be  made  into  macaroni,  and  for  the 
manufacture  of  a  very  nutritive  preparation,  "  granu- 
lated gluten;"  it  is  also  employed,  according  to  the 
recommendation  of  Bouchardat,  in  making  bread  for 
persons  afflicted  with  diabetes. 

Starch,  examined  with  a  microscope,  exhibits  flat- 
tened ovate  granules  of  different  size  in  various  plants, 
but  always  very  small.  Those  of  the  Rohan  potato 
have  a  length  of  0.185  mm.;  the  smallest  are  those  of 
the  CJienopodium.  quinoa  whose  length  is  0.002  mm. 

When  starch  is  heated  with  water  to  TO0,  the  gran- 
ules increase  from  20  to  30  times  their  original  volume, 
and  become  converted  into  a  tenacious  paste.  A  small 
quantity  of  the  starch  passes  into  solution,  and  to  this 
the  name  amidin  has  been  given.  Starch  paste  and 
the  solutions  of  starch  have  the  characteristic  property 
of  becoming  blue  in  contact  with  small  quantities  of 
iodine.  The  liquid  becomes  colorless  at  about  70°,  but 
regains  its  color  on  cooling.  If  to  this  blue  liquid  a 
solution  of  a  salt,  sodium  sulphate  for  instance,  be 
added,  we  obtain  a  dark-blue  floculent  precipitate.  This 
substance,  called  starch  iodide,  is  not  a  chemical  com- 
pound, but  a  sort  of  lake,  containing  variable  quanti- 
ties of  iodine  diffused  throughout  the  starch  and  solv- 


212  ORGANIC    CHEMISTRY. 

ent.  This  reaction  with  iodine  is  a  very  valuable  test 
for  starch,  but  is  open  to  several  fallacies,  and  apt  to 
mislead  in  inexperienced  hands. 

Until  lately,  it  has  been  claimed  that  starch  is  insol- 
uble in  water,  and  that  if  water  in  which  starch  has 
been  boiled  gives  with  iodine  the  characteristic  reaction 
of  this  substance,  it  is  due  to  particles  of  starch  suffi- 
ciently minute  to  pass  through  the  pores  of  the  filter. 
But  the  results  of  the  experiments  of  Maschke  and 
Thenard,  show  that  if  starch  is  heated  for  some  time 
at  100°,  it  is  partially  transformed  into  a  variety  solu- 
ble in  water.  This  substance  is  colored  by  iodine;  it 
furnishes,  on  evaporation,  a  gummy  solid  which  is  pre- 
cipitated by  alcohol  as  an  amorphous  powder. 

If  we  boil  starch  for  a  long  time  with  water  it  is 
converted  into  a  substance  called  dextrin.  The  pres- 
ence of  a  small  per  centage  of  sulphuric  acid  facilitates 
this  change,  which  is  soon  followed  by  the  transforma- 
tion of  the  dextrin  into  glucose.  The  sulphuric  acid 
is  not  at  all  altered  during  the  reaction. 

The  change  of  starch  into  glucose  also  takes  place 

O  O  i. 

when  water  containing  starch,  and  to  which  germinated 
barley  has  been  added,  is  heated  to  about  70°. 

This  transformation  is  due  to  a  substance  called 
diastase  (from  6iaffT&ffiS<  separation),  which  is  formed 
in  the  seed  during,  germination.  The  production  of 
diastase  on  the  formation  of  the  young  shoot,  explains 
how  etarch  becomes  soluble  and  serves  as  nutriment  to 
the  young  plant. 

The  ptyalin  of  the  saliva,  the  pancreatic  juice,  the 


STARCH.  213 

soluble  parts  of  beer  yeast,  gluten,  and  many  other  sub- 
stances, are  capable  of  producing  this  transformation 
of  starch  into  dextrin  and  glucose. 

It  has  generally  been  considered  that  the  molecule 
of  starch,  in  being  transformed  into  glucose,  simply 
united  with  one  molecule  of  water  directly,  thus: 

C6H1005  +  H20=C6H1206. 

Musculus,  however,  claims  to  have  established  that 
the  starch  is  lirst  transformed  into  a  soluble  metamer, 
and  this,  thereupon,  splits  up  into  dextrin  and 
glucose ; 

C18H3o015  +  H20=2C6H1005  +  C6H1206. 

Dextrin.  Glucose. 

By  further  action,  the  whole  of  the  dextrine  becomes 
converted  into  glucose,  (2-[3]  60-203). 

Starch,  heated  simply  to  about  160°,  is  also  changed 
into  dextrin. 

It  is  attacked  by  dilute  nitric  acid,  nitrous  vapors 
are  given  off  and  different  substances  are  produced, 
chiefly,  however,  oxalic  acid. 

If  starch  is  agitated  with  fuming  nitric  acid,  it  is 
dissolved  and  water  precipitates  from  the  solution  a 
nitrous  compound  which  is  explosive. 

The  alkalies,  in  concentrated  solutions,  when  heated 
with  starch  disorganize  and  dissolve  it.  Solutions  con- 
taining two  to  three  per  cent,  of  alkali,  accelerate  the 
formation  of  starch  paste. 


214  ORGANIC    CHEMISTRY. 

Starch  is  employed  in  the  laundry  and  therapeutic- 
ally  in  poultices,  injections  and  baths. 

Tapioca  is  the  starch  of  the  root  of  the  Jatropa 
mantfiot,  called  cassava  or  manioc. 

Sago  is  obtained  from,  the  pith  of  various  sago 
palms. 

Arroio-root  is  the  starch  of  the  Maranta  arundi- 
nacece*  and  one  or  two  other  tropical  plants. 

Salep  is  obtained  irom  the   Orchis  mascula. 

INULIN.  There  has  been  found  in  the  roots  of  the 
Jerusalem  artichoke,  of  the  chicory,  and  the  bulbs  of 
the  dahlia,  a  substance  isomeric  with  starch,  called 
inulin. 

LICHENIN.  There  is  extracted  from  certain  lichens 
and  mouses  a  substance  called  lichenin,  which  has  the 
property  of  swelling  in  cold  water  and  of  being  dis- 
solved in  boiling  water.  It  is  prepared  by  treating 
Iceland  moss  with  ether,  alcohol,  a  weak  solution  of 
potassa,  and  finally  with  dilute  hydrochloric  acid. 

There  exists  in  the  animal  organism  a  variety  of 
starch  designated  by  the  name  of  glycogen. 

DEXTRIN,   OK    DEXTRINE. 

C6H1005. 

To  prepare  dextrin,  starch  may  be  heated  with 
water  containing  a  small  quantity  of  sulphuric  or 
oxalic  acid  ;  the  operation  should  be  arrested  when 
the  liquid  gives  with  iodine  only  a  wine-colored  re- 
action. 


FLOUE.  215 

For  the  acids,  a  small  quantity  of  germinated  bar- 
ley may  be  substituted,  placed  in  a  bag  immersed  in 
the  liquid.  Dextrin  thus  prepared  always  contains 
glucose.  It  may  be  obtained  free  from  this  substance 
by  heating  starch  with  -|  its  weight  of  water  and  t  -Oa0  ^ 
of  nitric  acid. 

Dextrin  is  amorphous,  slightly  yellow,  very  soluble 
in  water,  insoluble  in  alcohol  and  concentrated  ether. 

It  is  used  somewhat  in  preparing  bandages  in  case 
of  fracture,  and  very  extensively  as  a  paste  for  calico- 
printers. 

Dextrin,  forms  viscid  adhesive  solutions  which  are 
used  for  the  same  purposes  as  gum-arabic.  The  mu- 
cilage used  by  the  U.  S.  government  for  postage 
stamps  is  composed  of  dextrin  two  ounces,  acetic 
acid  one  ounce,  water  five  ounces,  alcohol  one  ounce. 
Dextrin  may  be  distinguished  from  gum-arabic  by 
not  being  precipitated  on  adding  a  dilute  solution  of 
lead  acetate,  and  by  furnishing  with  nitric  acid  a  so- 
lution of  oxalic  acid  and  not  a  precipitate  of  mucic 
acid. 

FLOUE. 

Amylaceous  substances  are  of  great  importance  as 
food.  Wheat  and  other  cereals  are  the  most  import- 
ant sources  of  these  aliments. 

Starch,  as  also  sugar  and  the  neutral  carbohydrates, 
are  respiratory  foods  whose  principal  effect  is  the  pro- 
duction of  heat  by  being  oxidized,  or  burned,  in  the 
body. 


216  ORGANIC    CHEMISTRY. 

The  composition  of  four  of  the  leading  cereals  is 
herewith  given : 


Wheat,  14.0 

59.5 

7 

1.7 

14 

1.2 

1.5 

Eye,      16.0 

57.5 

10 

3.0- 

9 

2.0 

2.0 

Oats,     14.0 

53.5 

8 

4.0 

12 

5.5 

4.0 

Eice,      14.5 

77.0 

0.5 

7 

0.5 

0.7 

The  sticky,  elastic  substance  found  with  starch  in 
flour  is  gluten  (called  also  glutin),  and  is  a  mixture 
of  various  proximate  compounds,  but  chiefly  of  three; 
legumin,  or  vegetable  casein,  fibrin  and  gelatine. 

Flour  of  good  quality  is  dry  and  soft  to  the  touch; 
it  forms  with  water  an  elastic,  non-adhesive  dough. 

The  value  of  flour  depends  largely  upon  the  gluten 
it  contains,  though  not  as  stated  in  most  authors  upon 
the  percentage  of  this  substance,  but  upon  the  quality 
rather,  as  shown  by  recent  investigations  of  E.  W. 
Knnis  (26-74-1487). 

The  modern  ''patent  process,"  originating  in  Min- 
nesota, is  mainly  a  method  of  grinding  which  intro- 
duces into  the  flour  more  gluten  than  in  older  pro- 
cesses. 

GUM. 

C6H1005. 

This  substance  is  very  widely  distributed  in  the 
vegetable  kingdom.  Gums  either  swell  in  water  or 


GUM.  217 

are  dissolved,  imparting  to  it  a  mucilaginous  consis- 
tency. 

From  a  chemical  standpoint  they  are  essentially 
characterized  by  giving  a  precipitate  of  mucic  acid 
on  being  boiled  with  nitric  acid,  and  by  precipitating 
lead  subacetate. 

GUM- ARABIC,  AKABIN.  This  gum  exudes  from  dif- 
ferent species  of  acacias,  as  Acacia  arabica,  A.  sene- 
galensis,  A.  vera  ;  it  is  obtained  from  Arabia  and 
Senegal. 

According  to  Fremy,  gum-arabic  is  a  salt  formed 
by  the  combination  of  an  acid,  gummic  or  arable  acid, 
with  lime  and  potassa.  This  acid  may  be  isolated  by 
pouring  hydrochloric  acid  into  a  solution  of  gum,  and 
adding  alcohol;  an  amphorous  deposit  is  formed  which, 
dried  at  120°,  has  the  formula  C6II10O5.  This  acid  is 
very  soluble  in  water.  Its  solution  is  levogyrate,  like 
that  of  gum-arabic.  On  being  heated  to  150°  it  is 
transformed  into  a  substance  insoluble  in  water  called 
meta-gummic  acid,  whose  salts  are  likewise  insoluble. 
Gum-arabic  gives  with  ferric  salts  an  orange-colored, 
floculent  precipitate  soluble  in  acids. 

CEEASIN.  The  gum  which  exudes  from  cherry  and 
plum  trees  is  a  mixture  of  soluble  gummates  and  in- 
soluble meta-gummates ;  hence  it  is  only  partially 
soluble  in  water. 

Cerasin  becomes  soluble  on  being  boiled  with  water, 
as  the  meta-gurnmates  are  transformed  into  grummates 

o  O 

by  the  action  of  boiling  water. 

These  gums  heated  with  dilute  sulphuric  acid  furnish 
a  dextrogyrate  sugar. 


218  ORGANIC    CHEMISTRY. 

Gum-tragacanth  often  contains  starch. 

MUCILAGE  OR  BASSORIN.  There  exists  in  the  seeds 
of  the  quince  and  flax,  in  the  roots  of  the  marsh-mal- 
low and  in  portions  of  many  other  plants,  a  substance 
or  substances,  which,  exposed  to  the  action  of  boiling 
water,  furnish  a  thick  mucilage,  which  appears  to  con- 
sist of  a  soluble,  together  with  an  insoluble  substance. 
Nitric  acid  converts  this  mucilage  into  mucic  and  ox- 
alic acids.  Gum  and  mucilage  are  frequently  em- 
ployed as  emollients,  and  in  syrups,  also  extensively 
in  confectionery. 

PECTIN  GROUP.  Many  roots,  as  the  carrot,  beet, 
etc.,  also  green  fruits,  contain  a  neutral  gelatinous 
substance,  insoluble  in  water,  alcohol  and  ether,  called 
pectose.  It  is  that  which  gives  to  green  fruits  their 
harshness.  This  substance  is  modified  during  the 
ripening  of  the  fruit  and  becomes  soluble,  vegetable 
jelly,  or  pectin  (from  itrfKTiS,  a  jelly),  to  which 
Fremy  assigns  the  formula  C^H^O^. 

Pectin,  submitted  to  the  action  of  a  ferment  found 
in  the  cellular  tissues  of  vegetables,  called  pectase,  or 
of  cold,  very  dilute,  alkaline  solutions,  is  changed  into 
a  gelatinous  acid  called  peotosic  acid,  then  into 
another  substance  likewise  gelatinous,  which  is  known 
by  the  name  of  pectic  acid.  All  these  substances  are 
amorphous,  and  non-nitrogenous.  Their  formulae  are 
not  yet  definitely  determined. 

According  to  Fremy,  to  whom  we  are  indebted  for 
the  foregoing  facts,  the  jelly  obtained  from  the  current 
and  other  fruits  is  due  to  the  action  of  the  pectase  on 
the  pectin  of  these  fruits. 


LEGUMIN.  219 

These  substances  resemble  gums  in  producing,  on 
boiling  with  nitric  acid,  a  precipitate  of  mucic  acid. 

Much  doubt  still  exists  respecting  the  composition 
of  the  pectin  group. 

LEGUMIN  OR  VEGETABLE   CASEIN. 

Legumin  is  found  in  most  leguminous  seeds,  such 
as  sweet  and  bitter  almonds,  also  in  beans,  peas,  etc., 
the  latter  containing  about  25  per  cent.  It  is  con- 
sidered to  be  identical  with  casein  by  Liebig  and 
Woehler. 

It  may  be  obtained  by  digesting  coarsely  powdered 
peas  in  cold  or  tepid  water  for  two  hours,  allowing 
the  starch  and  fibrous  matter  to  subside,  and  then 
filtering  the  liquid.  It  forms  a  clear,  viscid  solution, 
which  is  not  coagulated  by  heat  unless  albumen  is  also 
present,  but,  like  emulsin  and  unlike  albumen,  it  is 
precipitated  by  acetic  acid.  It  is  coagulated  by  lactic 
acid,  also  by  alcoiiol ;  in  the  latter  case  the  precipitate 
is  redissolved  by  water. 

Acetic  acid,  diluted  with  8  to  10  parts  of  water,  is 
carefully  dropped  into  the  filtered  solution  obtained 
above,  and  the  legumin  is  precipitated ;  an  excess  of 
the  acid  should  be  avoided,  as  this  would  dissolve  the 
precipitate.  It  falls  in  the  shape  of  white  flakes,  and 
after  having  been  washed  on  a  filter  should  be 
dried,  pulverized  and  freed  from  adhering  fat  by 
digestion  in  ether.  Legumin  may  be  obtained  from 
lentils  with  the  same  facility  as  from  peas;  but  it  i& 


220  ORGANIC     CHEMISTRY. 

less  easily  procured  from  beans  (haricots),  in  con- 
sequence of  their  containing  a  gummy  matter  which 
interferes  with  its  precipitation  and  with  the  filtration 
of  the  liquids. 

The  chemical  properties  of  legumin  are  identical 
with  those  of  casein. 

Liebig  supposes  that  grape-juice  and  other  vegetable 
juices  which  are  deficient  in  albumen,  derive  their 
fermentation  power  from  soluble  legumin.  This 
principle  is  soluble  in  tartaric  acid,  and  to  its  presence 
he  ascribes  the  tendency  of  sugar  to  form  alcohol  and 
carbon  dioxide  instead  of  mucilage  and  lactic  acid. 

VEGETABLE  ALBUMEN. 

Vegetable  albumen  is  contained  in  many  plant- 
juices  and  is  deposited  in  flocculi  on  applying  heat  to 
such  liquids.  It  can  also  be  precipitated  by  nitric 
acid,  tannin  and  mercuric  chloride  precisely  likeanimal 
albumen.  Vegetable  albumen  is  composed  of  carbon, 
hydrogen,  nitrogen,  oxygen  and  sulphur.  There  is  no 
trustworthy  formula  for  this  substance. 


ANIMAL  CHEMISTRY. 


ANIMAL  CHEMISTRY. 


THE  substances  serving  as  materials  to  build  up  the 
structure  of  animals  are  of  a  varied  nature  ;  they  may, 
however,  be  grouped  into  four  classes : 

I.    FARINACEOUS    AND    SACCHARINE. 
II.    FATTY. 

III.  NITROGENOUS. 

IV.  MINERAL. 

We  have  already  studied  the  first,  second,  and 
fourth  of  these  classes  ;  we  will  now  proceed  to  examine 
those  of  the  third. 

NITEOGEKOUS  SUBSTANCES. 

It  is  generally  considered  that  these  substances  act 
a  different  part  in  the  organism  from  that  of  the 
saccharine  and  fatty  bodies,  these  latter  serving  ex- 
clusively as  heat  producers,  and  being  decomposed 
and  ultimately  consumed  (oxidized)  in  the  respiratory 
process,  have  therefore  received  the  name  of  respiratory 
foods.  The  nitrogenous  principles  (albumen,  casein, 
fibrin,  etc.)  serving  to  form  the  tissues  have,  likewise, 


224  ANIMAL    CHEMISTRY. 

received  the  denomination  plastic  foods.  The  distinc- 
tion thus  made  is  too  restricted,  as  we  shall  show 
later. 

Dumas  and  Cahours  have  proven  that  the  cereals 
and  other  plants  employed  as  food  contain  similar 
principles  to  those  found  in  flesh,  aiid  especially  that 
albuminoid  matter  exists  in  plants  as  well  as  animals. 

The  albumen  of  the  blood  and  that  of  wheat  are 
alike.  In  the  gluten  of  wheat  albuminoid  substances 
are  found  which  are  hardly  distinguishable  from  animal 
albumen,  fibrin,  and  casein. 

These  substances  are  characterized  : 

1st.  By  their  amorphous  structure.  The  three  sub- 
stances mentioned  never  crystallize ;  and  as  they  are 
also  non- volatile,  it  is  difficult  to  form  an  idea  of 
their  constitution,  and  represent  them  by  a  formula. 
This  formula  must  necessarily  be  very  complex,  as 
sulphur  forms  a  constituent,  though  present  only  in 
very  small  quantity.  Lieberkiihn  represents  their 
composition  by  the  expression 

C72H112N18S022. 

2nd.  By  their  extreme  instability.  The  apparently 
most  insignificant  circumstance  causes  them  to  pass 
from  a  soluble  to  an  insoluble  condition,  or  vice  rersd, 
and  produces  their  transformation.  They  are  decom- 
posed with  great  facility  under  the  action  of  air  and 
water.  This  very  exceptional  instability  constitutes  a 
property  of  the  greatest  interest,  as  it  permits  these 


NITROGENOUS    SUBSTANCES.  225 

substances  to  take  part  in  a  wonderful  manner  in  the 
varied  transformations  which  occur  in  living  organisms, 
and  it  might  be  said  that  they  are  the  principal  agents 
of  development  in  animals  and  plants.  We  shall  pre- 
sently see  that,  whatever  this  real  albuminoid  sub- 
stance may  be,  it  is  transformed  in  the  stomach  into 
identical  substances — peptones;  also,  that  during  the 
incubation  of  the  egg  the  albumen  is  seemingly  changed 
into  fibrin. 

CLASSIFICATION  — The  albuminoid  substances  are 
very  numerous,  and  may  be  classed  into  two  groups. 
Those  of  the  first  group  contain : 

Carbon  .....     53.5 

Hydrogen  .....       6.^ 

Nitrogen  .          „          .         .          .15.6 

Oxygen  .         .         „         „          .24.0 


100.0 

They  contain,  besides,  0.4  to  0.5  per  cent,  of  sulphur, 
unlike  those  of  the  second  group,  which  usually  contain 
no  sulphur.  In  addition,  they  often  contain  small 
quantities  of  mineral  substances. 

The  first  are  more  specially  designated  by  the 
name  of  albuminoid  substances,  as  albumen  is  the 
most  characteristic  member  of  the  group.  They  are 
also  known  by  the  name  of  protein  substances,  because 
Mulder  claimed  they  might  be  considered  as  formed 
of  a  single  radical  protein,  to  which  are  united 
variable  proportions  of  sulphur,  phosphorus,  etc. 


226  ANIMAL    CHEMISTRY. 

The  principal  members  of  this  group  are  :  albumen, 
of  which  several  modifications  are  recognized — the 
paralbumen,  metalbumcn,  etc. ;  fibrin,  of  which  there  are 
several  kinds — the  fibrin  of  the  blood,  fibrin  of  the 
muscles  or  mjosin  ;  casein,  regarded  by  some  as  a  com- 
bination of  albumen  and  alkali ;  hemoglobin  or  hemato- 
crystaUin,  the  colouring  matter  of  the  blood,  which  is 
distinguished  from  most  other  albuminoid  substances 
by  its  property  of  crystallizing ;  vitellin,  the  principle 
of  the  yolk  of  an  egg  ;  also,  several  principles,  icthin, 
ict/ilin  (i\6vs,  a  fish),  emydin,  the  first  two  obtained  by 
Valenciennes  and  Fremy  from  fishes'  eggs,  the  latter 
from  the  eggs  of  the  turtle. 

The  composition  of  these  substances  is  identical  or 
very  similar ;  a  formula  cannot  be  given  with  pre- 
cision. 

The  substances  of  the  second  group  generally  contain 
less  sulphur,  often  none,  and  appear  to  be  derived 
from  the  first  by  the  addition  of  nitrogen  and  oxygen. 
They  contain  in  per  cent. : 

Carbon 50.0 

Hydrogen          .         .         .         .  6.3 

Nitrogen  .....  16.8 

Oxygen     .  26.6 

100.0 

In  this  group  we  find — ossein,  the  organic  substance 
of  bones,  which  is  converted  into  gelatin  by  the  action 
of  boiling  water  ;  cartilage,  a  substance  very  analogous 


NITROGENOUS  SUBSTANCES.  227 

to  the  latter,  and  which  is  transformed  by  boiling 
water  into  chondrin ;  various  principles  concerned  in 
the  digestive  phenomena,  as  the  ptyalin  of  the  saliva, 
the  pepsin  of  the  gastric  juice,  the  mucin  of  the  mucus, 
the  pyin  of  pus,  etc.;  together  with  different  'pro- 
ducts which  result  from  the  action  of  the  gastric  juice 
upon  nitrogenous  substances,  and  which  are  called 
albuminoses  or  peptone*. 

GEN  ERAL  CHARACTERISTICS. — The  substances  of  these 
two  groups  on  being  heated  give  off  an  odour  of  burnt 
feathers.  On  distillation  they  produce  water,  empy- 
xeumatic  oils,  and  ammonium  carbonate,  sulphide,  and 
cyanide.  Carbon  remains  in  the  retort. 

The  substances  of  the  first  group,  on  being  heated  to 
50°  —  60°  with  a  solution  of  potassium  hydrate,  lose  their 
sulphur  and  are  dissolved.  If  we  add  acetic  acid  to 
this  liquid,  dark  grey  flakes  of  a  substance  (protein 
of  Mulder)  are  thrown  down.  The  substances  of  the 
second  group  do  not  possess  this  property.  On  pro- 
tracted boiling  with  a  caustic  alkali  they  yield : 

Tyrosin  ....  C9HUN03 
Leucin  ....  CCH13N02 
Glycocol  ....  C2H5N02 

Some  are  soluble,  others  insoluble,  in  water  ;  they  are, 
in  general,  insoluble  in  alcohol,  ether,  and  chloroform. 

Hydrochloric  acid  diluted  with  1,000  times  its  weight 
of  water  dissolves  some,  a  few  swell  up  simply ;  upon 
others  it  has  no  effect.  Hot  concentrated  hydrochloric 


228  ANIMAL    CHEMISTRY. 

acid  attacks  all  these  substances,  and  the  resulting  pro- 
ducts are  the  same  as  those  which  are  obtained  (and 
more  readily)  with  sulphuric  acid.  These  products  are 
chiefly  glycocol,  leucin,  and  tyrosin.  Nitric  acid 
colours  them  yellow  (xanthoproteic  acid).  Ordinary 
phosphoric"  md  acetic  acids  do  not  precipitate  the 
substances  of  the  second  group,  but  redissolve  them 
even  when  coagulated. 

Solutions  of  albuminoid  substances  in  potassium 
hydrate  do  not  precipitate  copper  salts.  Heated  with 
oxidizing  reagents,  as  a  mixture  of  potassium  bichro- 
mate and  sulphuric  acid,  they  furnish  several  members 
of  the  series  of  fatty  acids,  and  the  aldehyds  corre- 
sponding to  these  acids.  The  albuminoid  substances  are 
decomposed  during  the  process  of  respiration  in  the 
same  manner  as  when  under  the  action  of  oxidizing 
agents. 

Ammoniacal  solutions  of  copper  dissolve  albuminoid 
substances  as  they  dissolve  cellulose,  which  fact  would 
seem  to  connect  the  albuminoid  substances  with  cellu- 
lose, and  to  give  certain  weight  to  a  theory  of  Hunt, 
which  considers  the  albuminoid  substances  as  cellulose 
which  has  combined  with  the  elements  of  ammonia  and 
parted  with  the  elements  of  water. 


ALBUMEN. 


This  substance  is  found  both  in  vegetable  organisms 
(cereals)  and  in  animal  organisms  (serum  of  the  blood, 
white  of  egg,  lymph,  chyle). 


ALBUMEN.  229 

Wurtz  obtains  it  by  mixing  white  of  eggs  with 
twice  its  weight  of  water,  straining  and  precipitating 
the  albumen  with  a  solution  of  lead  acetate.  The 
precipitate  is  washed  with  cold  water  and  decomposed 
with  a  current  of  carbon  dioxide,  which  precipitates  the 
lead,  while  the  albumen  remains  in  solui  u  If  this 
liquid  be  evaporated  at  a  temperature  below  59°,  it  is 
deposited  in  a  soluble  state ;  if  a  quantity  be  heated  to 
63°,  a  portion  of  the  albumen  is  coagulated  ;  but  if  the 
temperature  is  not  raised  above  74°,  four-fifths  remain 
dissolved  ;  consequently  it  would  seem  as  though  there 
were  several  kinds  of  albumen,  but  the  nature  and 
amount  of  foreign  substances  present  are  the  principal 
causes  of  these  differences.  If  the  solution  is  very  dilute, 
coagulation  will  not  take  place.  Heating  is  not  the 
only  mode  of  producing  this  change ;  alcohol,  acids — 
with  the  exception  of  a  few,  such  as  hydrogen  phos- 
phate, H3P04,  hydrogen  tartrate  and  hydrogen  acetate — 
the  metallic  salts,  creosote,  tannin,  etc.,  also  effect  it. 
The  alkalies  prevent  this  action.  Grautier  obtains  albu- 
men by  dialysis. 

Soluble  albumen  is  without  odour,  and  is  more  soluble 
in  saline  than  in  pure  water.  Very  dilute  hydrogen 
chloride  precipitates  solutions  of  albumen,  the  precipi- 
tate being  redissolved  by  an  excess  of  the  acid.  This 
solution  does  not  contain  albumen,  but  a  substance 
probably  isomeric  with  it,  which  is,  however,  more 
easil}r  obtained  from  muscular  tissue :  it  is  called 
syntonin. 

-Among  the  products  of  the  putrefaction  of  albumen, 


230  ANIMAL    CHEMISTRY. 

Nencki  (18-'78-71)  has  obtained  butyric  and  vale- 
rianie  acids. 

Insoluble  albumen  heated  with  water  in  a  sealed  tube 
to  150°  or  160°,  dissolves,  but  this  modification  is  not 
coagulated  again  by  heat. 

Animal  albumen  containing  1.5  per  cent,  of  soda 
may  be  regarded  as  a  weak  acid,  and  in  presence  of 
alkaline  solutions  it  dissolves.  A  few  drops  of  potassium 
hydrate  are  sufficient  to  form  with  albumen  a  gela- 
tinous compound,  called  potassium  albuminate,  which 
is  soluble  in  water  and  no  longer  coagulable  by  heat. 
This  liquid,  diluted  with  water,  is  rendered  turbid  by 
acetic  acid,  but  the  precipitate  is  redissolved  by  an 
excess  of  acid. 

Albumen  of  the  Serum. — This  is  easily  soluble  in  con- 
centrated hydrochloric  acid,  and  is  not  precipitated 
by  ether.  Injected  into  the  veins  it  is  absorbed. 

Egg  Albumen. — This  is  more  difficultly  soluble  in 
concentrated  hydrochloric  acid,  and  is  precipitated  by 
ether.  Injected  into  the  veins  it  is  absorbed  in  very 
minute  quantities,  and  can  be  found  again  in  the 
urine. 

Albuminoid  substances  (fibrino-plastic  substance,, 
fibrinogene)  are  found  in  the  blood;  they  have  the 
general  characteristics  of  albumen,  but  are  distinguished 
from  it  by  being  precipitated  with  carbon  dioxide.  The 
soluble  matter  of  the  crystalline  lens  of  the  eye  also 
possesses  this  property. 

The  coagulation  of  albumen  by  alcohol,  tannin,  and 
heat,  and  the  consequent  formation  of  a  sort  of  net- 


F1KK1X.  231 

work  which  fills  the  whole  liquid,  and  which  precipi- 
tates all  matters  held  in  suspension,  as  well  as  certain 
substances  in  solution,  explains  the  employment  of 
white  of  egg  for  the  clarifying  of  wine,  syrups, 
also  as  a  mordant,  and  the  use  of  blood  in  sugar 
refining. 

FIBKIN. 

The  blood  of  animals  coagulates  spontaneously 
shortly  after  leaving  the  body.  This  is  due  to  the 
solidification  of  a  substance  called  fibrin,  which,  on 
solidifying,  forms  a  sort  of  net-work,  imprisoning  the 
globules  of  the  blood,  and  gives  rise  to  a  gelatinous 
mass  (clot).  The  researches  made  to  explain  this 
process  of  coagulation  will  be  mentioned  further  on. 
Ether  accelerates  this  coagulation.  Sodium  sulphate 
and  glycerine  retard  or  even  arrest  it.  Pure  fibrin 
may  be  obtained  by  beating  fresh  blood  with  twigs. 
It  attaches  itself  to  the  twigs,  and  if  then  washed 
with  water,  and  afterwards  with  alcohol,  we  obtain  a 
dai'k-grey  filamentous  substance,  which  is  insoluble 
fibrin.  It  may  also  be  obtained  by  working  clotted 
blood  in  water  as  long  as  it  colours  the  water. 

Fibrin  is  insoluble  in  water,  hot  or  cold,  but  if 
heated  with  it  in  close  vessels  it  gradually  loses  its 
property  of  solidifying.  It  is  soluble  in  alkaline  solu- 
tions, and  precipitable  again  by  acids. 

Lehman  has  concluded  from  his  analyses  that  fibrin 
is  oxidized  albumen.  Smee  affirms  that  if  oxygen 
be  passed  into  defibrinated  serum,  heated  to  about 


232  ANIMAL    CHEMISTRY. 

36°,  the  albumen  is  gradually  transformed  into 
iiocks  of  fibrin.  This  subject  needs  further  investi- 
gation. 

Fibrin  of  blood  swells  when  treated  with  water  con- 
taining 1- 1000th  part  of  hydrochloric  acid.  It  is 
dissolved  in  stronger  hydrochloric  acid,  and  is  then 
converted  into  syntonin.  Freshly  precipitated  fibrin 
is  dissolved  at  35°  to  40°  in  water  containing  certain 
salts,  and  notably  in  that  containing  potassium  nitrate 
or  sodium  sulphate ;  it  decomposes  hydrogen  peroxide. 

The  albumen  in  the  egg  is  transformed  into  fibrin 
during  incubation  ;  inversely,  if  fibrin  be  kept  under 
water,  it  gradually  becomes  soluble,  and  this  liquid, 
like  albumen,  is  coagulated  by  the  action  of  heat. 

Varieties  of  Fibrin. — The  gluten  which  constitutes 
the  plastic  substance  of  cereals,  has  the  composition 
and  general  properties  of  fibrin. 

When  well-washed,  muscular  tissue  is  macerated 
with  water  containing  ten  parts  in  100  of  sea  salt, 
it  is  partially  dissolved ;  if  this  solution  is  poured 
into  water  a  gelatinous  mass  is  obtained  on  agitation. 
This  substance  washed  on  a  filter  has  received  the 
name  of  wt/onin,  or  mnsculin. 

It  is  soluble  in  acids,  in  dilute  alkalies,  and  in  a  solution 
of  sea  salt ;  this  last  solution  coagulates  at  about  60°. 

Myosin,  on  dissolving  in  dilute  acids,  is  changed 
into  synfotiin,  which,  like  myosin,  is  soluble  in  acids 
and  alkalies,  but  from  which  it  is  distinguished  by  its 
insolubility  in  salt  water.  Syntonin  is  more  easily  ob- 
tained by  macerating  flesh,  which  has  been  completely 


CASEIN.  233 

deprived  of  blood  by  prolonged  washing  with  water, 
containing  0.01  of  hydrogen  chloride.  The  macerated 
flesh  is  almost  entirely  dissolved  This  solution  is 
filtered  and  exactly  neutralized  with  sodium  carbo- 
nate ;  the  syntonin  is  precipitated  in  a  grey,  flocculeut 
form. 

Blood  fibrin  contains  about :  C  =  52.6  ;  H  —  7.0  ; 
N  =  16.6;  S  =  1.2  to  1.6;  0  =  the  difference, 
authors  not  agreeing  very  closely  as  to  its  exact  com- 
position. 

CASEIN. 

Casein  is  the  nitrogenous  principle  of  milk.  To 
extract  it,  milk  is  brought  to  boiling,  and  a  few  drops 
of  acetic  acid  added.  An  abundant  coagulum  of  casein 
mixed  with  butter  (caseum)  is  formed.  The  pure 
casein  is  separated  by  washing  this  coagulum  several 
times  with  water,  alcohol,  and  ether. 

Casein  is  difficultly  soluble  in  water,  but  is  dissolved 
by  alkalies.  It  forms  with  the  alkalies  soluble  com- 
pounds, and  with  the  other  bases  insoluble  salts. 
Casein  has  the  composition  of  the  albuminates  of 
soda,  differing,  however,  from  these  by  various  re- 
actions, and  by  the  amount  of  its  levogyrate  action  on 
the  polarized  ray  of  light. 

Solutions  of  casein  are  not  coagulated  by  heat,  they 
simply  become  covered  with  a  white  film.  They  are 
precipitated  by  acetic  and  other  organic  acids ;  milk 
curdles  spontaneously,  on  account  of  the  lactic  acid 
formed  in  it. 


234  ANIMAL    CHEMISTRY. 

Many  substances  such  as  tannin,  alcohol,  plants 
with  acid  reactions  and  several  others,  the  flowers 
of  the  artichoke,  of  the  thistle,  of  the  butterwort 
(Pinguicula  vulgaris),  and,  above  all,  rennet  from 
the  stomach  of  a  sucking  calf,  cause  coagulation  in 
milk. 

LEGUMIN,    OR    VEGETABLE    CASEIN. 

Braconnot  extracted,  by  means  of  water,  from  the 
seeds  of  leguminous  plants  (beans,  peas)  a  substance 
called  legumin,  and  which  has  a  close  analogy  to  casein, 

VITELLIN. 

This  substance  is  prepared  by  treating  boiled  yolk 
of  egg  with  ether,  which  extracts  the  fatty  matters. 
There  remains  a  white  substance  insoluble  in  water. 
It  can  be  obtained  in  a  soluble  state  by  mixing  fresh 
yolk  of  egg  with  water.  The  clear  liquid  coagulates 
at  about  70°,  like  albumen,  of  which  it  possesses  the 
general  properties. 

OSSEIN,    GELATIN,    CHONDRIN. 

The  compounds  of  this  second  group  are  probably 
formed  of  a  single  substance,  whose  elements  are 
differently  aggregated,  and  also  mixed  with  variable 
quantities  of  mineral  substances.  They  are  insoluble 
in  water,  alcohol,  and  acetic  acid ;  they  swell  in  cold 
and  dissolve  in  hot  alkaline  solutions. 

The  organic  substance  of  bones  (ossein],  treated  with 


OSSEIN,    GELATIN,    CHONDKIN.  235 

boiling  water,  furnishes  gelatin.  The  cartilages,  under 
the  same  circumstances,  furnish  a  product  which  has 
most  of  the  properties  of  gelatin,  but  which  differs 
from  it  in  being  precipitated  by  acids  and  by  alum ; 
it  is  called  chondrin. 

To  prepare  gelatin,  bones  are  treated  with  boiling 
water  to  remove  the  grease,  then  macerated  with  water 
acidulated  with  hydrochloric  acid,  which  dissolves  the 
mineral  portions  (calcium  carbonate  and  phosphate). 
The  organic  portions  remain  undissolved,  retaining  the 
form  of  the  bone,  yet  flexible  and  elastic.  The  solu- 
tion is  poured  off  and  employed  in  the  manufacture  of 
calcium  hypophosphite,  or  of  composts.  The  organic 
substance,  well  freed  from  acid  by  washing  in  milk  of 
lime  or  a  weak  solution  of  sodium  carbonate,  is  put 
into  boilers  with  water,  which  is  gradually  raised  to 
the  boiling  point.  The  organic  matter  gradually 
enters  into  solution.  It  is  now  decanted  into  a  vat 
heated  over  a  water  bath,  where  various  undissolved 
substances  are  deposited,  and  whence  it  is  drawn 
into  wooden  moulds,  where  it  solidifies.  The  gela- 
tin is  removed  from  the  moulds,  cut  into  thin 
slices,  dried  on  nets,  and  is  now  the  glue  of  commerce. 

The  tendons,  skin,  horns,  and  clippings  of  hides 
are  also  employed  for  the  manufacture  of  glue ;  they 
are  simply  treated  with  boiling  water. 

Darcet  showed  in  1817  that  gelatin  could  be 
made  directly  from  bones  by  digesting  them  with 
steam  heated  to  104°.  The  solution  obtained  has  the 
appearance  of  soup,  and  it  was  hoped  to  thus  pro- 


ANIMAL    CHEMISTRY. 

duce  a  very  substantial  nutriment  quite  cheaply ;  but 
it  has  been  found  that  the  nutritive  power  of  this 
substance  is  very  small,  and  the  use  of  "  gelatine 
food"  has  been  abandoned. 

The  purest  gelatin  is  the  ichthyocol,  or  tsinglaw. 
It  is  made  chiefly  in  Moldavia  and  on  the  borders 
of  the  Caspian  Sea,  from  the  swimming  bladders  of 
the  sturgeon  and  of  the  acipenseres. 

Pure  gelatin  is  solid,  colourless,  and  transparent. 
Boiling  water  dissolves  it  in  large  quantities.  The 
liquid  solidifies  to  a  jelly  on  cooling  :  one  per  cent. 
is  sufficient  to  give  water  a  gelatinous  consistency. 
Continued  boiling  with  water  deprives  it  of  the  pro- 
perty of  solidifying  in  the  cold,  or  gelatinizing. 
Boiled  with  dilute  sulphuric  acid,  it  is  transformed 
into  glycocol. 


DIGESTION.  237 


DIGESTION. 

An  organized  being  cannot  live  without  nourishment, 
that  is,  without  obtaining  from  the  bodies  which 
surround  it  the  materials  necessary  for  the  formation 
and  the  metamorphoses  of  its  tissues. 

The  food  of  animals  is  rarely  assimilable  in  the  state 
in  which  it  is  found  in  nature ;  therefore  it  must 
undergo  a  preparation  which  shall  render  it  absorb- 
able.  Hence  the  existence  of  a  particular  function, 
digestion.  This  function  is  performed  by  the  digestive 
organs.  They  vary  in  complexity  with  different 
animals  :  they  differ  in  form  according  to  the  nature  of 
the  food. 

In  man  the  digestive  apparatus  is  very  complex.  If 
the  food  is  solid  it  must  be  dissolved.  Every  liquid, 
however,  is  not  immediately  assimilable ;  it  often  also 
must  be  transformed  in  chemical  and  physical  charac- 
ter. We  shall  now  follow  the  food  through  the  process 
of  digestion,  and  explain  the  manner  in  which  each 
class  of  aliments  becomes  soluble  and  absorbed. 


In  the  mouth  the  food  is  subjected  to  mechanical 
action  under  the  influence  of  a  liquid  secreted  by  glands 


'238  SALIVA. 

V 

situated  in  pairs  on  each  side  of  the  mouth  (parotid, 
submaxillary,  and  sublingual). 

Tubes  have  been  introduced  into  the  ducts  of  the 
parotid  and  submaxillary  glands,  and  by  exciting 
secretion,  the  products  of  these  glands  have  been 
separately  examined.  The  salivas  are  not  alike,  and 
have  different  digestive  properties,  their  combination, 
mingled  with  mucus,  constituting  "  mixed  saliva." 

The  parotid  secretion  is  a  clear  liquid,  not  viscous, 
and  slightly  alkaline,  containing  1.0  to  1.6  per  cent,  of 
solid  substances,  among  which  are  alkaline  chlorides 
and  phosphates;  an  organic  substance  soluble  in 
alcohol  and  water ;  another,  ptyalin,  which  is  the  most 
important  principle  of  the  saliva  ;  and  finally,  potassium 
sulphocyanide. 

Ptyalin  contains  potassium,  sodium,  and  calcium. 
It  resembles  compounds  of  albumen  with  these  bases, 
is,  however,  gelatinous  and  not  coagulable  by  heat  or 
by  most  metallic  salts.  It  is  precipitated  by  mercury 
bichloride,  lead  acetate,  and  tannin. 

The  submaxillary  glands  are  dependent  upon  the 
chorda  tympani  nerve,  and  the  branches  of  the  great 
sympathetic  nerve.  The  secretion  varies  as  it  is  excited 
by  the  one  or  the  other  of  these  nerves. 

The  liquid  secreted  after  an  excitement  of  the  great 
sympathetic  nerve  is  thick,  alkaline,  and  rich  in  solid 
substances.  The  liquid  obtained  by  the  excitement  of 
the  chorda  tympani  is  less  concentrated.  It  is  alkaline, 
and  contains  epithelial  cells,  small  quantities  of 
albumen,  globulin,  and  a  substance  (muciu)  to  which. 


SALIVA.  239 

its  mucilaginous  appearance  is  due,  and  which  is  not 
found  in  the  parotid  secretion. 

The  liquid  of  the  suhlingual  glands  has  not  as  yet 
been  obtained  pure  ;  concerning  it  we  know  only  that 
it  is  a  viscous  solution. 

Buccal  mucus  has  a  slight  acid  reaction. 

Mixed  saliva  is  a  turbid,  ropy,  inodorous,  tasteless 
liquid.  It  deposits  debris  of  epithelium.  In  man  its 
density  varies  from  1.007  to  1.008. 

It  has  an  alkaline  reaction,  and  contains  from  0.7 
to  1.0  per  cent,  of  solid  substances,  of  which  about 
one-third  is  inorganic,  chiefly  alkaline  carbonates, 
phosphates,  and  chlorides.  It  contains  in  solution 
more  carbon  dioxide  than  even  venous  blood. 

1,000  parts  of  saliva  contain  : — 

Mitscherlich.     Jacubowitsch. 

Water         .         .         .  984.50  992.16 

Solid  substances  .         .  10.50  4.84 

Ptyalin       .         .         .  5.25  1.34 

Mucus  and  epithelium  0.05  1.62 

Sulphocyanogen  .         .  .  .  0.06 

According  to  Longet,  potassium  sulphocyanide  is  a 
normal  product  of  the  saliva.  It  is  recognized  by 
placing  in  the  saliva  a  ferric  salt,  which  is  coloured  red. 
This  salt  does  not  exist  in  the  blood,  perspiration, 
lacrymal  fluid,  or  pancreatic  juice.  Its  amount  is 
always  very  small,  and  its  presence  in  saliva  is  doubted 
by  Grautier. 


240  ANIMAL    CHEMISTRY. 

On  boiling  saliva  it  becomes  opalescent,  on  account 
of  the  precipitation  of  albumen.  Nitric  acid  colours  it 
yellow  by  attacking  the  albuminoid  substances.  Alcohol 
precipitates  from  it  ptyalin,  mixed  with  nitrogenous 
compounds. 

Saliva  exposed  to  the  air  becomes  covered  with  a 
film  of  calcium  carbonate,  and  concretions  of  this 
substance  are  often  found  in  the  salivary  ducts  and  on 
the  teeth. 

An  adult  can  secrete  about  1,200  to  1,500  grains  of 
saliva  in  twenty-four  hours  ;  the  actual  quantity  varies 
with  the  dryness  of  the  food. 

The  saliva  possesses  evident  mechanical  functions  in 
digestion.  It  facilitates  mastication  by  impregnating 
the  food  ;  it  lubricates  the  bolus,  and  renders  degluti- 
tion possible ;  and  finally,  by  virtue  of  its  viscous  and 
frothy  consistency,  it  imprisons  air,  which  passes  into 
the  oesophagus  with  the  food. 

Deglutition  is  favoured  much  more  by  the  mucus 
than  by  the  saliva  proper  ;  this  mucus  is  secreted  by 
glands  found  in  the  walls  of  the  mouth  and  pharynx. 

It  lias  been  contested  that  the  saliva  has  for  a 
chemical  function  the  saccharification  of  starch,  as  the 
food  does  not  remain  but  for  an  instant  in  contact  with 
it,  and  as  the  amount  of  saliva  secreted  is  independent 
of  the  amount  of  starch  in  the  food.  The  proportion  of 
saliva  increases  when  the  food  is  dry  or  hard,  and 
diminishes  when  it  is  soft,  even  when  it  is  formed  of 
boiled  starch ;  in  short,  it  seems  to  vary  inversely 
with  the  humidity  of  the  food. 


SALIVA.  241 

It  has  been  remarked  that  salivary  glands  exist  in  a 
rudimentary  state  in  animals  which  do  not  masticate 
their  food. 

Mialhe  indicates  the  following  experiment :  Chew 
some  unleavened  bread,  then  place  it  on  Berzelius  test 
paper.  Rub  another  portion  of  the  same  bread  with 
water,  and  filter  the  liquid.  The  first  is  not  coloured  by 
iodine,  and  becomes  brown  on  being  boiled  with 
potassa.  The  second  turns  blue  with  iodine. 

According  to  the  same  chemist  this  action  is  due  to 
ptyalin,  an  amorphous  substance  insoluble  in  alcohol, 
of  which  I  to  2  per  cent,  is  present  in  the  saliva,  and 
which  is  able  to  saccharify  as  much  as  2,000  times  its 
own  weight  of  starch ;  it  also  effects  this  change  with 
extreme  rapidity.  This  substance  has  then  the  property 
of  vegetable  diastase. 

It  has  also  been  shown  directly  by  Messrs.  Mialhe, 
Longet,  and  Sehiif,  that  even  if  pure  gastric  juice  itself 
does  not  have  the  property  of  saccharifying  starch,  this 
saccharificatiou  by  the  saliva  is  not    arrested  by  the 
acidity  of  the  gastric  juice,  and  consequently  the  saliva 
which    is    carried   into    the    stomach   can    continue   to 
saccharify  the  starchy  food  in  this  organ.     It  is  then 
very  probable  that  the  saliva  performs  this  service  in 
the  process  of  digestion,  though  some  claim  that  this  ac- 
tion is  only  on  food  not  yet  thoroughly  mixed  with  gas- 
tric juice.     It  appears  to  have  no  action  on  sugar,  gum, 
cellulose,  or  albuminoid  compounds. 

In  inflammatory  diseases  of  the  mouth,  as  in  the 
thrush,  the  saliva  becomes  acid,  and  weak  alkaline 


242  ANIMAL    CHEMISTRY. 

beverages  are  prescribed.  In  Brigkt's  disease  urea  is 
found  in  the  saliva.  Mercury  is  also  present  in  cases 
of  mercurial  salivation.  After  the  use  of  preparations 
containing  iodine  and  bromine,  these  substances  are 
found  in  this  secretion. 

The  tartar  of  the  teeth  contains,  in  100  parts,  25 
of  organic  substances,  75  of  inorganic  substances, 
formed  chiefly  of  calcium  phosphate ;  the  remainder 
is  calcium  carbonate,  iron,  and  silica. 

.       GASTRIC   JUICE. 

The  gastric  juice  is  secreted  in  the  mucous  mem- 
brane  of    the    stomach    by   an    immense   number   of 
glandular  follicles,  though  not  secreted  when  the  stomach 
is  empty. 

As  soon  as  food  enters  the  stomach,  the  mucous 
membrane  swells,  assumes  a  blood-red  colour,  and 
the  gastric  juice  is  at  once  secreted. 

The  secretion  can  also  be  excited  by  irritating 
this  membrane  by  ice,  cold  water,  wine,  gall,  coffee, 
bismuth  subnitrate,  sodium  bicarbonate,  and  alkaline 
substances  in  general.  According  to  L.  Corvisart, 
gastric  juice  secreted  by  mechanical  irritation  is  most 
rich  in  digestive  principles.  We  can  easily  procure 
gastric  juice,  or  rather  a  mixed  liquid,  formed  of  this 
juice,  stomachic  mucus,  and  saliva,  by  making  an 
aperture  in  the  stomach  of  an  animal,  and  it  may  be 
obtained  free  from  saliva  by  previously  ligating  the 
oesophagus. 


GASTRIC    JUICE. 


243 


The  gastric  juice  may  be  freed,  to  a  great  extent, 
from  the  mucus  by  nitration. 

The  mucus  is  alkaline.  When  the  stomach  has 
not  received  food  for  a  long  time,  the  mucous  secre- 
tion alone  is  produced,  and  the  liquid  in  the  stomach 
may  become  alkaline.  The  gastric  juice  forms  an 
almost  colourless  liquid,  with  a  faint  odour,  decidedly 
acid  reaction,  and  is  somewhat  denser  than  water. 
It  may  be  preserved  for  a  very  long  time  without 
alteration,  it  loses  its  digestive  properties  on  ebulli- 
tion, but  is  not  altered  by  cold. 

Schmidt  obtained  the  following  analysis  of  gastric 
juice  mixed  with  saliva : — 


Organic  matter 
Hydrochloric  acid 
Potassium  chloride 
Sodium  „     . 

Calcium  „ 

Ammonium      „     . 
Calcium  phosphate 
Magnesium      ,, 
Iron  „ 

Water  . 


Man. 

Dog. 

8.79 

17 

.12 

0.20 

3 

.05 

0.55 

1 

.12 

1.46 

2 

.5-0 

0.06 

.62 

.47 

1 

.73 

0.14 

0 

.23 

0 

.08 

988.80 

973 

.08 

1000.00        1000.00 


These  analyses  are  the  mean  of  several.  It  is, 
moreover,  very  evident  that  the  composition  of  this 
liquid,  as  well  as  that  of  others  in  the  body,  must 


244  ANIMAL    CHEMISTRY. 

vary,  not  only  in  the  quantity,  but  sometimes  even 
in  the  nature  of  their  constituents. 

All  analyses  of  the  gastric  juice  show  that  it  is 
an  acid  substance.  The  nature  of  this  acid  has  been 
the  object  of  much  discussion  between  different 
experimenters,  and  principally  between  Messrs.  Blond- 
lot  and  Schmidt.  According  to  the  first,  the  acidity 
is  due  to  acid  calcium  phosphate ;  according  to  the 
second,  to  hydrochloric  acid. 

It  is  true  that  calciTim  phosphate  is  found  in 
the  gastric  juice,  but  according  to  Lehmann  and 
Schiff,  this  salt  is  formed  \>y  the  action  of  the 
gastric  juice  on  the  substance  of  the  bones,  and 
does  not  exist  in  the  gastric  juice  of  animals  de- 
prived of  this  food.  Consequently  this  substance  is 
not  a  normal  and  constant  constituent  of  gastric 
juice. 

Schmidt  points  to  the  following  experiment.  Pie 
determines  the  amount  of  >  chlorine  in  a  known  weight 
of  gastric  juice,  by  means  of  silver  nitrate,  and  also 
determines  the  bases.  Now,  the  quantity  of  hydro- 
chloric acid  corresponding  to  the  weight  of  chlorine 
determined  by  analysis,  is  always  more  than  suffi- 
cient to  neutralize  the  bases  found ;  hence  he  con- 
cludes that  hydrochloric  acid  exists  in  a  free  state 
in  the  gastric  juice. 

Moreover,  having  determined  the  amount  of  free 
acid  by  saturating  the  gastric  juice  with  a  standard 
solution  of  a  base,  he  found  that  the  amount  of  free 
acid  was  about  equal  to  the  weight  of  the  excess 


GASTRIC   JUICE.  245 

of    hydrochloric    acid     resulting    from    the    previous 
determination. 

Lactic  acid  is  generally  found  in  the  gastric  juice, 
and,  according  to  Messrs.  Bernard  and  Barreswill, 
this  is  probably  the  acidifying  principle ;  according 
to  others,  it  exists  there  only  when  starchy  food  is  used. 
Thus,  recently,  Rabuteau  (9-80-61),  by  neutralizing 
gastric  juice  with  quinia  evaporating,  treating  with 
amyl-alcohol,  and  obtaining  the  crystallized  quinia, 
salt  dissolved  in  the  amyl-alcohol,  found  the  free  acid 
of  the  stomach  to  be  hydrochloric  acid ;  he  was  not 
able  to  discover  lactic  acid  in  the  gastric  juice. 

Butyric  and  acetic  acids  have  also  been  detected  in 
the  gastric  juice. 

When  lactic  acid  is  distilled  with  a  dilute  solution 
of  a  chloride,  hydrochloric  acid  is  found  in  the  pro- 
duct :  possibly  the  hydrochloric  acid  is  produced  in 
the  stomach  by  the  reaction  of  the  lactic  acid  on  the 
alkaline  chlorides  (?'). 

It  is  difficult,  according  to  Biche,  to  admit  that 
the  hydrochloric  acid  is  present  in  an  absolutely  free 
state,  for  calcium  carbonate  does  not  completely 
remove  the  acidity  of  the  gastric  juice ;  and  if  this  be 
submitted  to  distillation,  the  hydrochloric  acid  comes 
over  only  as  one  of  the  final  products.  The  fact  has 
also  been  directly  established  that  the  albuminoid 
substances  unite  with  mineral  acids,  forming  com- 
pounds possessing  an  acid  reaction,  and  which  have 
lost  certain  properties  of  free  acids. 

E.  Maly  (1 — 173,  227)  has  come  to  the  conclusion, 


246  ANIMAL   CHEMISTRY. 

through  experiments  lately  made  as  to  the  origin  of 
the  acid  in  gastric  juice,  that  pure  gastric  juice  con- 
tains no  lactic  acid,  and  that  the  origin  of  the  hydro- 
chloric acid  of  the  stomach  is  not  due  to  the  decom- 
position of  the  chlorides  present  by  lactic  acid.  The 
source  of  the  free  hydrochloric  acid  of  the  stomach 
is,  according  to  Maly,  to  be  sought  in  a  disasso- 
ciation  of  the  chlorides,  without  the  intervention  of 
an  acid. 

Charles  Blchet,  however  (62 — '77),  has  been  studying 
the  properties  of  the  human  gastric  juice  upon  the  person 
of  the  patient  on  whom  Verneuil  successfully  performed 
gastrotomy.  He  has  reached  the  following  conclusions  : 
1.  The  acidity  of  the  gastric  juice,  whether  pure  or 
mixed  with  food,  is  equivalent  to  1'7  grammes  of 
hydrochloric  acid  to  a  thousand  grammes  of  fluid.  2. 
Acidity  increases  slightly  at  the  end  of  digestion,  and 
is  independent  of  the  quantity  of  liquid  contained  in 
the  stomach.  Wine  and  alcohol  increase,  but  cane- 
sugar  diminishes  it.  3.  If  acid  or  alkaline  matters  are 
introduced,  the  gastric  juice  tends  to  return  to  its 
normal  acidity.  4.  The  mean  duration  of  digestion  is 
from  three  to  four  and  a  half  hours  or  more.  Food 
does  not  pass  successively,  but  in  masses,  -x  Accord- 
ing to  four  analyses  made  by  a  modification  of 
Schmidt's  method,  it  was  proved  that  free  hydrochloric 
acid  exists  in  the  gastric  juice.  6.  It  is  possible  to 
extract  all  the  lactic  acid  contained  in  the  stomach,  and 
to  prove  that  there  is  ono  part  lactic  acid  to  nine  parts 
hydrochloric  acid.  7.  Following  the  method  of  Bertlie- 


GASTRIC    JUICE.  247 

lot,  that  is,  by  agitation  with  anhydrous  ether  and 
deprived  of  alcohol,  it  can  be  shown  that  lactic  acid  is 
free  in  the  gastric  juice.  8.  The  question  so  long  in 
controversy  as  to  the  nature  of  the  free  acid  in  the 
stomach  seems,  according  to  Bichet,  almost  solved,  and 
it  may  be  said  that  in  every  1,000  grammes  of  gastric 
juice  there  are  1*53  grammes  of  hydrochloric  acid  and 
0-43  of  lactic  acid, 

PEPSIN. — Observation  has  shown  that  if  an  infusion 
of  the  mucous  membrane  of  the  stomach  be  made,  and 
the  liquid  acidified,  it  dissolves  albuminoid  substances 
as  well  as  the  gastric  juice.  The  mucous  membranes 
of  the  other  organs  do  not  possess  this  property. 

Wasman  was  the  first  to  extract  from  the  mucous 
membrane  of  the  stomach  the  active  agent  of  this 
transformation. 

It  is  an  albuminoid  substance  known  by  the  names 
of  pepsin,  chytnosin,  and  f/asterase  pepsin.  The  best 
method  of  preparing  pepsin  is  that  of  Schmidt. 
Grastric  juice  is  neutralized  with  lime-water,  filtered, 
evaporated  to  the  consistency  of  syrup,  and  precipitated 
with  concentrated  alcohol.  The  pepsin  is  re-dissolved 
in  water,  precipitated  with  lead  acetate  ;  the  precipitate 
is  collected  and  decomposed  by  a  current  of  hydrogen 
sulphide.  The  sulphur  is  separated  by  filtering,  and 
the  liquid  containing  pepsin  is  evaporated  to  dryness 
at  a  low  temperature.  The  method  by  Bruecke  we 
omit,  as  it  appears  to  give  a  less  pure  product. 

Pepsin  is  a  yellowish  gummy  substance,  soluble  in 
water.  Dissolved  in  50,000 — 60,000  parts  of  acidu- 


248  ANIMAL   CHEMISTRY. 

lated  water,  it  dissolves  coagulated  white  of  egg  in  six 
or  eight  hours.  Alone  it  does  not  possess  this  dis- 
solving power. 

Heat  does  not  coagulate  pepsin,  but  destroys  its 
digestive  properties. 

The  union  of  pepsin  and  an  acid  is  necessary  for  diges- 
tion. The  acids  of  the  stomach  have  been  replaced  by 
most  of  the  other  acids,  with  success.  Artificial  diges- 
tion may  be  very  easily  produced  with  pepsin  and  an 
appropriate  amount  of  acid,  or  better,  with  gastric 
juice  itself.  If  the  proportion  of  acid  is  too  large  the 
action  is  stopped.  The  most  suitable  temperature  is 
38°  to  40° ;  the  action  is  very  slow  at  50°  and  at  12° ; 
no  action  takes  place  at  100°  or  at  5°. 

Liquid  albumen  does  not  coagulate  in  the  stomach,  it 
is  dissolved,  and  the  solution  is  not  coagulable  by  heat 
or  acids.  Coagulated  albumen  is  converted  into  a  soft, 
nacreous  substance,  then  into  a  sort  of  pulp,  which  is 
gradually  dissolved.  According  to  some  chemists, 
albumen  is  absorbed  directly. 

Fibrin  is  more  energetically  attacked  by  this  secre- 
tion than  ordinary  albumen,  which  seems  to  prove  that 
fibrin  is  neutral,  while  the  alkali  of  the  albumen,  by 
saturating  the  acidity  of  the  gastric  juice,  retards  its 
action.  Fibrin  of  the  blood  is  attacked  more  rapidly 
than  that  of  the  muscles.  At  first  it  swells,  then 
changes  into  a  grey  powder,  which  is  finally  dissolved. 
(jrluten  is  dissolved  very  readily.  Liquid  casein  co- 
agulates, and  afterwards  dissolves  in  the  same  manner 
as  coagulated  albumen. 


GASTRIC   JUICE.  249 

The  name  peptones  is  given  to  the  products  of  the 
transformation  of  albuminoid  substances  by  the  action 
of  gastric  juice.  J.  Murk  has  lately  observed  the  pre- 
sence in  saliva  of  a  peptone  ferment  (60-'?6-1800). 

Peptones  are  soluble  in  water,  coagulated  by  alcohol, 
lead  acetate,  mercury  bichloride,  and  tannin.  They 
differ  from  albumen,  inasmuch  as  their  solutions  are 
not  coagulable  by  heat ;  peptones-  obtained  from 
osseous  and  gelatinous  tissues  are  not  precipitated  by 
potassium  ferrocyanide. 

According  to  Meissner,  the  gastric  juice  produces 
with  albumen,  at  first,  a  substance,  parapeptotw, 
identical  with  syntonin,  which  afterwards  forms  various 
other  peptones. 

Peptone  (a)  is  precipitated  by  nitric  acid,  also  by 
potassium  ferrocyanide,  acidified  with  acetic  acid. 

Peptone  (b)  is  precipitated  by  the  latter  of  these 
reagents. 

Peptone  (c)  is  precipitated  by  neither  reagent. 

Hoppe-Seyler  and  Grautier  doubt  the  existence  of 
these  peptones. 

The  gastric  juice  does  not  dissolve  all  the  nitrogenous 
substances  of  the  food.  A  portion  escapes  its  action, 
and  is  subsequently  transformed  in  the  intestines.  It 
is  generally  admitted  that  gastric  juice  has  no  action 
on  fatty  substances. 

Starch  is  not  aifected  by  the  gastric  juice,  but  it 
seems  to  be  substantiated  that  the  saliva  continues  its 
action  on  these  substances  in  presence  of  the  gastric 
juice.  (Bruecke,  Gautier,  Besanez.  Ed.  of  1878,  p.  831.) 


250  ANIMAL    CHEMISTRY. 

In  catarrh  of  the  stomach  the  mucous  secretion  is  very 
abundant,  and  various  organic  acids  are  formed. 


LIVER.  BILK 

Besides  bile  there  have  been  extracted  from  the  liver 
glucose,  a  substance  analogous  to  starch,  called  yli/cogeiie, 
fatty  substances,  and  various  nitrogenous  products, 
viz.,  leucin,  tyrosin,  and  xanthauin. 

The  quantity  of  bile  secreted  is  quite  large.  Guinea- 
pigs  secrete  in  twenty-four  hours  a  quantity  of  bile 
amounting  often  to  several  times  the  weight  of  their 
liver.  In  order  to  extract  it  from  these  or  other 
animals  the  gall  bladder  is  emptied,  or  the  biliary 
ducts  are  ligatured,  and  an  opening  made  in  them. 

The  bile  before  entering  ^the  gall-bladder  is  odourless. 
On  remaining  in  this  vesicle  it  acquires  a  strong  odour, 
a  bitter  taste,  becomes  concentrated,  and  forms  a  viscous 
greenish  or  brown  liquid.  Its  density  varies  from 
1.0-^5  to  1.033. 

Its  normal  reaction  is  slightly  alkaline.  It  is  co- 
agulated by  acids ;  the  coagulum  is  formed  of  two 
acids,  taurocholic  and  choUc,  or  glycocholic  acids. 

Human  bile  contains  from  9  to  18  per  cent,  of  solid 
substances ;  a  less  quantity  is  found  in  the  bile  of  the 
ox  and  pig.  More  than  half  of  this  residue  is  formed 
of  combinations  of  the  acids  just  named,  with  different 
bases,  though  mainly  with  soda. 

The  bile  may  therefore  be  regarded  as  essentially 
a  saponaceous  compound.  The  other  solid  constituents 


COMPOSITION     OF    BILE. 


251 


of  the  bile  are — a  neutral  organic  substance  called 
cholesterin,  a  colouring  matter,  neutral  fatty  substances 
and  salts ;  urea  is  sometimes  found  in  it. 

Strecker  has  extracted  a  base  from  bile  which  he  calls 
citolin.  This  substance  is  identical  with  nenrin,  which 
has  been  extracted  from  the  brain  and  yolk  of  egg. 
Its  formula  is  C5H15N02. 


COMPOSITION  OF  BILE. 

(GORUP-BESANEZ.) 


Man  of  49    Woman    of  i  Man  of  68  ; 

years,  de-    29  years,  de-  years,  killed"6**!'  G1( 

capitated,      capitated,      by  a  fall.    |    -    .  an 


Water        .... 

822.7           898.1 

908.7 

!     828.1 

Fatty  substances 

177.3           101.9 

91.3 

171.9 

Salts  of  the  biliary  acids     . 

107.9             56.5 

} 

i) 

Fat     

Cholesterin 

}    47.3 
} 

j    30.9 

73.7 

148.0 

Mucus,  colouring  matters  . 

22.1 

14.5 

17.6 

23.9 

Mineral  salts 

10.8 

6.3 

— 

— 

i 

The  ash  of  ox  gall  contains  i — 

Sodium  chloride      ,         0 
Sodium  phosphate  *         c 
Potassium     „          c         . 
Calcium         ,?         c         0 
Magnesium  „ 
Ferric  oxide 
Silica 


27.70 
16.00 
7.50 
3.02 
1.52 
1.52 
0.36 


Small  quantities  of  nitrogen  have  also  been  found, 


252  ANIMAL    CHEMISTRY. 

and  considerable  proportions  of  carbon  dioxide  ;  this 
last  gas  may  be  extracted  by  a  mercury  pump. 
Animal  food  augments  the  quantity  of  carbon 
dioxide. 

ACIDS  OF  THE  BILE. — Human  bile  contains  much 
more  taurocholic  than  glycocholic  acid. 

The  former  alone  exists  in  the  bile  of  the  dog ;  it 
abounds  in  the  bile  of  serpents  and  fishes.  Grlycocholic 
acid  is  wanting  in  carnivorous  animals.  Both  exist 
abundantly  in  the  bile  of  the  ox. 

The  bile  of  the  pig  contains  special  acids  :  hyoglyco- 
cholic  acid,  and  taurohyocholalic  acid. 

In  order  to  obtain  the  two  acids  of  the  bile,  neutral 
lead  acetate  is  added  to  ox-gall,  which  precipitates  the 
glycocholic  acid  as  a  lead  salt.  This  compound  is  col- 
lected, washed,  boiled  with  85  per  cent,  alcohol,  and  the 
boiling  liquid  filtered.  It  is  then  exposed  to  a  current 
of  hydrogen  sulphide  while  yet  warm  ;  the  lead  sul- 
y)hide  is  thrown  on  a  filter  and  washed  until  the  liquid 
becomes  turbid.  The  glycocholic  acid  precipitates  out 
•of  the  solution,  and  is  purified  with  boiling  water. 

The  alkaline  taurocholate  is  not  precipitated  by  the 
lead  acetate.  To  the  first  liquor  lead  subacetate  is 
added  until  the  precipitate  takes  on  a  fatty  consistency  ; 
this  precipitate  is  collected,  washed,  and  suspended  in 
water.  A  current  of  hydrogen  sulphide  is  passed 
through  the  water,  the  liquid  filtered  and  evaporated. 
The  taurocholic  acid  is  deposited  as  a  white  powder. 

GTLYOOOHOLIC  ACID,  C.,(;H4SNO(,,  forms  white  needles 
moderately  soluble  in  alcohol.  One  part  is  soluble  in 


TAIIROGHOLIC    ACID.  253 

100  parts  of  "boiling  and  300  parts  of  cold  water. 
With  alkalies  and  barium  it  forms  soluble  crystalline 
salts. 

Boiling  alkaline  solutions  and  dilute  acids,  separate 
it  into  cholalic  acid  and  glycocol  by  combining  with 
water. 

C26H43N06    +   H20    =    C24H4005    +    C2H5N02 

Glycocholic  aeid.  Water.  Cholalie  acid.  Glycocol. 

On  being  boiled  with  concentrated  hydrochloric  acid 
or  sulphuric  acid,  it  furnishes  the  following  products  : 

Cholonicacid     .         .         .     Co0H41N05 
Choloidic    .  '      .         .         .     C,4H3804 
Dyslisin      ....     C24H3003 


TAUROCHOLIC  ACID,  C^H^NOifS,  has  not  yet  been 
obtained  crystalline.  It  dissolves  in  alcohol  and  water, 
imparting  to  these  an  acid  reaction.  It  is  partly 
destroyed  by  the  evaporation  of  its  aqueous  solution. 
It  combines  with  one  molecule  of  water  on  being 
boiled  with  alkaline  solutions,  cholalic  acid  and  taurin 
being  formed. 

C2f;H45N07S    +    H20    =  C24H4005  +    C2H7N03S 

Taurocholic  acid.  Cholalic  acid.  Taurin. 

THE  BILE  FERMENT.  —  "W.   Epstein   and  J.  Muller 

c 


254.  ANIMAL   CHEMISTRY. 

(60-1875-679)  have  lately  investigated  the  influence 
of  different  substances  upon  the  action  of  the  ferment 
of  the  liver.  Dilute  aqueous  solutions  of  carbolic 
acid  (1  :  300)  do  not  prevent  the  transformation  of  the 
glycogen  into  sugar  if  brought  into  contact  with  fresh, 
finely-chopped  liver;  yet  this  carbolic  acid  solution 
protects  the  liver  from  putrefaction  for  a  long 
time.  Five  per  cent,  solutions  of  sodium  chloride 
and  sodium  sulphate  do  not  prevent  or  influence 
the  transformation  of  the  glycogen  of  the  liver. 
Alkalies  render  the  change  slower,  acids  prevent  it 
entirely  ;  even  when  very  dilute  they  greatly  retard 
it.  The  action  of  acids,  however,  is  only  tran- 
sitory ;  on  neutralizing  them  the  action  of  the  ferment 
at  once  begins.  Whether  carbon  dioxide  prevents 
fermentation  or  not,  has  not  been  ascertained  with 
certainty.  The  supposition  of  Tiegel  that  the  change 
of  the  glycogen  of  the  liver  into  sugar  is  connected 
with  the  destruction  of  the  blood -corpuscles  was  not 
confirmed  by  the  experiments  of  Epstein  and  Miiller. 
They  prepared  from  liver — moistening  it  with  carbolic 
acid,  drying  at  30°,  extracting  with  glycerine,  and 
precipitating  with  alcohol — a  ferment  peculiar  to  liver, 
which  converts  glycogen  into  sugar  very  rapidly  and 
easily. 

TAURIN,  C.2H7N03S. — This  substance  may  be  pre- 
pared by  boiling  ox-gall  with  an  excess  of  hydrochloric 
acid  for  several  hours.  Filter  and  add  to  the  liquid 
five  or  six  times  its  weight  of  boiling  alcohol,  and 
allow  to  cool  slowly.  The  taurin,  which  is  almost 


CHOLESTER1M.  255 

insoluble   in   alcohol,   will    separate  out   in  colourless 
rhomboidal  prisms. 

Taurin  has  been  produced  artificially  by  Strecker,  on 
heating  isethionate  of  ammonia  at  200°.  This  salt 
loses  one  molecule  of  water,  and  tauriu  remains. 

(C2H4,S02)"  ioa  =  H20  +  [(C2H4,  SO,)",  HO]' ) 
NH4J  HJ1 

This  substance  is,  therefore,  an  amide  like  glycocoL 

Taurin  is  found  in  the  muscles  of  certain  mollusks. 

CHOLESTERIN.  —  C2GH440,H.,0.  —  This  substance  is 
widely  diffused  in  the  animal  organism.  Biliary  cal- 
culi are  almost  entirely  formed  of  it  ;  it  is  found  in 
the  blood,  yolk  of  eggs,  spleen,  r>us,  in  various  tumours, 
in  the  nerves  and  brain.  It  is  easily  extracted  from 
biliary  calculi,  which  are  pulverized,  suspended  in  alco- 
hol with  animal  charcoal,  and  the  mixture  brought  to 
boiling  ;  after  some  time,  the  liquid  is  filtered.  The 
cholesterin  deposits  on  cooling. 

Berthelot  has  shown  that  cholesterin  has  been 
wrongly  classed  among  the  neutral  fatty  substances  ; 
it  is  not  saponifiable.  He  considers  it  a  monatomic 
alcohol. 


He    has   prepared   the   ethers  of  cholesterin    by  the 
action  of  acids  : — 


Lt)t>  ANIMAL    CHEMISTRY. 

Acetic  ether  Q  2u  Q  j  0. 

This  alcohol  is   dehydrated  by  anhydrous  phosphoric 
acid,  producing  the  carbo-hydride  : — 

Co6H42  cholesterilene. 

Cholesterilene  is  colourless,  odourless,  and  tasteless, 
crystallizable  in  brilliant  rhomboidal  tablets,  fusible  at 
145°,  and  volatile  at  360°.  Water  does  not  dissolve  it ; 
it  is  slightly  soluble  in  cold  alcohol,  and  quite  soluble 
in  boiling  alcohol  and  ether.  It  is  soluble  in  the 
taurochlorates.  It  turns  the  plane  of  polarization  to 
the  left. 

Heated  with  a  few  drops  of  nitric  acid  it  becomes 
yellow,  and  this  yellow  substance,  on  being  touched 
with  a  drop  of  ammonium  hydrate,  turns  red.  Sul- 
phuric acid  colours  cholesterin  red  ;  if  chloroform  is 
added,  a  blood-red  colour  is  obtained  which,  before 
disappearing,  becomes  successively  violet,  blue,  and 
green. 

According  to  Flint,  cholesterin  is  an  excrementitious 
substance,  which  results  from  the  disintegration  of 
nervous  tissue,  as  it  is  not  found  in  the  blood  entering 
the  brain,  but  is  found  in  the  blood  of  the  veins  which 
leave  it.  Also,  though  absent  in  muscular  tissue,  it 
is  always  found  in  the  nerves.  It  is  absorbed  by  the 
blood  and  eliminated  by  the  liver,  as  it  is  abundant  in 
the  blood  of  the  hepatic  artery  and  the  vena  porta, 


COLOURING    MATTERS    OF    THE    BILE.  257 

while  little  or  none  is  found  in  the  blood  of  the  sub- 
hepatic  veins.  During  digestion  it  is  changed  into  a 
substance  called  stercorin,  and  evacuated  in  this  state ; 
also,  when  cholesterin  is  not  discharged  into  the  in- 
testines, a  decrease  in  the  production  of  stercorin  is 
observed.  The  retention  of  cholesterin  in  the  blood 
gives  rise  to  the  serious  malady  cholesteremia. 

COLOURING  MATTERS  OF  THE  BILE. — The  hile  fur- 
nishes two  colouring  matters :  one  brown,  called 
bilirubin,  cholepyrrhin,  or  bilifulvin ;  the  other  green, 
called  bilkentin. 

Bilirubin,  C16H18N.,Oo. — This  substance  may  be  pre- 
pared by  agitating  fresh  bile  with  water,  ether,  and 
dilute  hydrochloric  acid,  which  do  not  dissolve  it,  then 
with  chloroform ;  the  bilirubin  dissolves,  and  is  de- 
posited on  evaporation  in  orange-red  crystals. 

This  body  is  dissolved  by  alkalies.  It  forms  with 
lime  a  sort  of  lake,  sometimes  also  found  in  the  body 
(biliary  pigment). 

This  substance  has  been  found  not  only  in  the  liver, 
but  also  in  the  brain,  in  cases  of  haemorrhage,  and  in 
the  placenta  of  dogs. 

Biliverdin,  C16H20N205,  appears  to  be  a  product  of 
alteration  of  bilirubin.  It  is  first  formed  in  the  putre- 
faction of  bile,  is  then  changed  spontaneously  into 
biliprasin,  C]6H22N,00  (?). 

Biliverdin  may  be  prepared  by  allowing  an  alkaline 
solution  to  stand  for  a  time  in  the  open  air  ;  this  solu- 
tion is  then  precipitated  with  hydrochloric  acid.  Both 
colouring  malters  are  precipitated  in  this  manner,  and 


"268  ANIMAL    CHEMISTRY. 

the  biliverdin  may  be  removed  by  treating  the  precipi- 
tate with  alcohol,  which  dissolves  this  substance  alone. 
Stoedler  announces  that  he  has  extracted  from  bile 
two  other  colouring  matters — bilifuscin  and  bilihumin. 
The  former  has  been  recently  studied  by  Simony 
(111-73-181). 

ACTION  OF  THE  BILE  ON  FOOD.  —  -The  bile  is  not 
simply  extracted  from  the  blood  by  the  liver,  but  is 
elaborated  by  it ;  the  biliary  acids  are  not  found  in 
any  other  part  of  the  body,  and  the  blood,  in  passing 
through  the  liver,  loses  its  fibrin  and  a  portion  of  its 
albumen.  It  has  also  been  proved  that  the  bile  is 
formed  in  the  liver,  by  removing  this  organ  from 
frogs  ;  when,  after  this  operation,  biliary  acids  were  no 
longer  found.  Lehmann  believes  that  the  fibrin,  wholly  or 
in  part,  taken  up  by  the  liver,  is  transformed  into  glycogen. 

The  bile  neutralizes  the  gastric  juice,  yet  this  satu- 
ration is  not  complete ;  the  acids  of  the  bile  thus 
liberated  have  perhaps  a  certain  utility  in  the  intestines. 

The  bile  has  no  digestive  action  on  amylaceous 
matters,  but  assists  in  the  digestion  of  fatty  substances. 
Messrs.  Schmidt  and  Bidder  have  shown  that  dogs 
assimilate,  per  kilogramme  and  per  hour,  under  ordi- 
nary conditions,  0.465  gramme  of  fat,  while  only  0.093 
gramme  is  absorbed  when  the  bile  has  been  removed 
through  a  fistula.  The  chyle  of  a  dog  fed  with  fat 
contains  at  least  3  per  cent,  of  this  matter ;  if  the 
action  of  the  bile  be  prevented  by  a  fistula,  this  quan- 
tity will  fall  below  1  per  cent. 

On   agitating  bile  with  oil,    it   forms   a  rapid    and 


ACTION    OF    THE    BILE    ON    FOOD.  259 

persistent  emulsion.  Oils  rise  higher  in  a  capillary 
tube  when  moistened  with  bile  than  when  moistened 
with  water. 

Bile  has  no  action  on  albuminoid  substances  in  their 
ordinary  condition.  It  precipitates  acid  solutions  of 
albuminoid  matter,  but  an  excess  of  bile  re-dissolves 
these  precipitates.  It  is  therefore  not  impossible  that 
the  bile  takes  part  in  the  digestion  of  the  albuminoid 
substances,  acidified  but  not  absorbed  in  the  stomach. 

Bile  is  found  throughout  the  smaller  intestines  ;  it 
attaches  itseli  to  their  folds,  and  by  its  adhesive  charac- 
ter retains  the  non-absorbed  food,  and  facilitates  the 
action- of  the  intestinal  fluids. 

Bile  is  not  found  in  the  large  intestine,  although  we 
find  there  cholalic  acid,  taurin,  and  dislysin  ;  glycocol 
has  not  been  found.  The  excrements  contain  also 
taurin,  dislysin,  and  cholalic  acid,  but  Hoppe-Seyler, 
by  determining  the  amount  of  this  latter  acid  in  the 
excrements,  has  shown  that  the  greater  part  disappears 
in  the  intestine. 

The  bile  appears  to  prevent  putrefaction  of  the  con- 
tents of  the  intestine. 

The  bile,  therefore,  after  what  we  have  stated,  would 
seem  to  be  a  secretion,  and  also  an  excretion. 

But  little  is  known  in  regard  to  the  formation  of  the 
immediate  principles  of  the  bile.  We  owe  to  Lehman 
an  ingenious  and  probable  hypothesis  regarding  the 
formation  of  the  acids  of  the  bile. 

According  to  his  theory  the  fatty  substances,  espe- 
cially olein,  play  an  important  part  in  their  produc- 


260  ANIMAL    CHEMISTRY. 

tion.  In  fact,  the  cholalic  acid,  like  oleic  acid  in 
contact  with  alkalies,  is  broken  up  into  an  acetate  and 
palmitate.  Also  the  blood  in  passing  through  the 
liver  loses  fat ;  the  amount  of  bile  increases  when  the 
food  is  rich  in  fatty  and  nitrogenous  substances,  and 
the  amount  of  fat  increases  as  the  bile  diminishes  and 
diminishes  as  the  bile  increases. 

The  bases  to  which  these  acids  are  united  are 
derived  from  the  blood,  for  it  has  been  proved  that  the 
blood  contains  less  salts  on  leaving  the  liver  than  on 
entering  it. 

The  nitrogen  of  these  acids,  in  the  taurin  and 
glycocol,  is  obtained  from  the  albuminoid  matters,  as 
the  blood,  in  passing  through  the  liver,  leaves  behind  a 
notable  quantity  of  these  substances.  The  sulphur  of 
these  products  has  the  same  origin. 

Bilirubin  appears  to  have  great  analogy  with 
hsematoidin,  which  results  from  the  alteration  of  the 
colouring  matter  of  the  blood  ;  hence  it  would  seem 
rational  to  admit  that  the  colouring  matter  of  the  bile 
is  derived  from  that  of  the  blood,  and  that  the  htemo- 
globin  is  destroyed  in  the  liver.  This  explains  why  no 
blood  is  found  in  the  bile. 

The  biliary  secretion  augments  two  or  three  hours 
after  eating,  and  increases  up  to  the  thirteenth  or 
fourteenth  hour.  Vegetable  food  produces  bile  in  less 
quantity  and  less  concentrated  than  animal  food. 

Fatty  aliments,  mixed  with  nitrogenous  substances, 
increase  both  the  amount  of  the  bile  and  its  richness  in 
solids. 


PANCREATIC   JUICE.  261 

The  injection  of  calomel  increases  the  secretion  of 
We. 

The  biliary  substances  diminish  in  diabetes,  in 
tuberculous  affections,  in  dropsy,  and  typhus ;  increase 
in  choleric  persons,  and  in  diseases  of  the  heart  and 
abdomen.  The  biliary  secretion  diminishes  in  fevers. 

BILIARY  CALCULI. — These  are  divided  into  biliary  or 
cystic,  hepatic,  and  hepato-cystic  calculi,  according  to 
their  origin. 

They  are  composed  of  cholesterin,  mixed  with  the 
colouring  matters  of  bile  and  mucus.  Cholesterin  forms 
80  per  cent,  of  these  calculi.  To  extract  the 
cholesterin  the  powdered  calculus  is  treated  with 
boiling  alcohol ;  on  cooling,  beautiful  nacreous  blades  of 
cholesterin  separate  out. 

Ox  bile  (gall)  is  employed  for  removing  grease.  It 
may  be  prevented  from  putrefying  by  evaporating  to 
the  consistency  of  syrup. 

We  shall  speak  of  glycogen  under  the  head  of 
nutrition. 

PANCREATIC    JUICE. 

The  pancreatic  juice  is  a  liquid,  colourless  and  some- 
what viscous,  having  a  saline  taste.  Its  density  is  not 
uniform,  as  it  contains  variable  proportions  of  solid 
matter,  which  have  been  found  to  amount  to  as  high  as 
11  per  cent. 

Its  reaction  is  alkaline,  and  due  to  sodium  hydrate. 
'The  most  important  proximate  principle  of  this  juice  is 


262  ANIMAL    CHEMISTRY. 

an  albuminoid  substance  called  pancreatin.  In  it  is 
likewise  found  a  fatty  substance,  also  leucin,  tyrosin, 
xanthin,  and  several  salts,  among  which  are  sulphates 
and  chlorides. 

This  juice  owes  to  the  paucreatin  present  its  property 
of  coagulating  with  heat,  alcohol,  and  acids.  This  fact 
led  to  the  belief,  formerly,  that  the  albuminoid  principle 
of  this  juice  was  albumen  ;  this  is  not  true,  however, 
as  the  coagulum  formed  by  alcohol  re-dissolves  in  water 
and  re-assumes  the  viscous  appearance  and  the  charac- 
teristics of  pancreatic  juice. 

Pancreatiu  is  prepared  by  pouring  85  per  cent,  al- 
cohol into  pancreatic  juice.  White  flakes  are  formed, 
which  are  soluble  in  water,  yielding  a  solution  which 
possesses,  to  a  high  degree,  the  property  of  converting 
starch  into  sugar.  Jenneret  states  (18-77-389)  that 
the  action  does  not  require  oxygen. 

Pancreatic  concretions  contain  variable  proportions 
of  nitrogenous  organic  matter  and  calcium  carbonate 
and  phosphate. 

ACTION  OF  PANCREATIC  JUICE.— This  juice  appears 
to  act  upon  the  three  classes  of  organic  aliments ;  it 
promptly  forms  an  emulsion  with  neutral,  fatty  sub- 
stances, and  is  even  capable  of  saponifying  them.  Its 
action  is  most  rapid  at  about  35° ;  its  action  is  arrested 
by  acids,  even  the  acidity  of  the  gastric  juice  retarding 
its  action.  It  has  been  found,  also,  that  in  chyle 
neutral  fatty  substances  predominate  over  acid  fats, 
and  it  is  therefore  believed  that  the  pancreatic  juice 
renders  fats  assimilable  by  forming  an  emulsion  with 


ACTION    OF    PANCREATIC    JUICE.  263 

them.  The  bile  and  intestinal  secretion  share  with  the 
pancreatic  juice  this  property,  for  it  has  been  shown 
that  the  chyle  contains  emulsions  of  fat,  after  the  ligature 
of  the  pancreatic  duct :  their  action,  however,  is  very 
weak,  as  Bernard  found  that  if  the  pancreatic  juice  be 
prevented  from  entering  the  intestines,  the  greater  part 
of  the  fatty  substances  are  found  unchanged  in  the 
excrements. 

Corvisart,  Kiihne,  and  others  have  shown  that  this 
juice  dissolves  fibrin  and  coagulates  albumen,  trans- 
forming them  into  assimilable  products,  analogous  to 
the  peptones.  It,  however,  will  act  alone,  whatever 
may  be  the  state  of  the  liquid,  while  pepsine  requires 
the  co-operation  of  an  acid.  According-  to  Schiff  the 
functions  of  the  spleen  are  connected  with  those  of  the 
pancreas,  as  the  pancreatic  juice  has  no  action  on  albu- 
minoid substances  after  the  spleen  has  been  removed. 

Moreover,  and  this,  according  to  Bouchard  at  and 
Sandras,  is  its  principal  role,  the  pancreatic  juice  is  the 
chief  agent  in  effecting  the  transformation  of  farinaceous 
food. 

The  transformation  of  starch  into  glucose  is  slow,  as 
farinaceous  mattej  has  been  found  in  the  intestines 
twenty-four  hours  after  eating.  It  is  probable  that 
only  a  small  quantity  of  the  starch  is  absorbed  in  the 
form  of  glucose,  the  greater  part  being  normally 
absorbed  in  the  form  of  dextrine.  The  transformation 
continues,  absorption  having  been  accomplished,  under 
the  action  of  the  ferment  absorbed  at  the  same  time, 
with  the  dextrine. 


264  ANIMAL    CHEMISTRY. 

Pancreatic  juice  is  rapidly  decomposed  in  contact 
with  the  air. 

Claude  Bernard  states  that  an  infusion  of  pancreas, 
or  a  solution  of  pancreatic  juice,  after  having  stood  in 
the  air  for  some  time,  assumes  an  intense  red  colour  on 
the  addition  of  chlorine  water.  Nencki  (18-'78-79)  is 
of  the  opinion  that  pancreatic  digestion  is  essentially  a 
process  of  putrefaction. 


INTESTINAL    FLUIDS. 

These  liquids  are  complex  products  even  when  the 
ducts  conducting  the  bile  and  pancreatic  juice  to  the 
intestines  are  closed,  as  there  are  several  varieties  of 
glandular  apparatus  which  secrete  liquids  throughout 
the  length  of  the  intestinal  canal.  Colin  has  shown 
that  mucus  is  also  secreted.  This  physiologist,  by 
binding  the  intestine  at  two  points,  about  two  metres 
apart,  was  enabled  to  obtain  about  one  hundred  grammes 
of  the  liquid  secreted  by  the  glands  of  Lieberkiihn,  and 
having  removed  the  mucus  by  deposition  and  filtration, 
he  examined  its  properties. 

It  is  a  limpid  liquid,  slightly  yellowish,  secretion, 
whose  density  is  1.010  and  reaction  very  alkaline. 
Saturated  with  an  acid  it  is  coagulated  by  heat.  It  is 
also  coagulated  by  alcohol  and  precipitated  by  lead 
acetate. 

This  fluid  continues  the  transformation  of  farinaceous 
substances  into  dextrine  and  sugar,  and  forms  emulsions 


INTESTINAL    FLUIDS.  265 

with  fatty  matters.  Although  possessing  an  alkaline 
reaction,  it  acts  upon  albuminoid  substances.  Thus, 
according  to  Bidder  and  Schmidt,  flesh  and  albumen 
coagulated  by  heat,  and  enclosed  in  the  intestines  by 
ligature,  soften,  dissolve,  and  are  digested ;  consequently, 
the  intestinal  fluid  completes  the  digestion  of  nitro- 
genous substances  :  it  is  not  known  what  constitutes  its 
active  principle.  Thiry  found  in  pure  intestinal  fluid 
from  a  dog : 

Water  .  97.585 

Albuminates  .  .  0.802 

Other  organic  substances  ,  .         0.734 

Inorganic  substances  .  .          0.879 

The  gases  of  the  smaller  intestine*  are  chiefly  carbon 
dioxide  and  hydrogen.  In  the  larger  intestine  these 
gases  are  mingled  with  methane,  and  traces  of  hydrogen 
sulphide  ;  the  methane  amounts  to  as  high  as  50  per 
cent,  of  this  volume  when  the  food  is  vegetable. 

The  excrements  contain  10  to  15  per  cent,  of  solid 
substance,  of  which  6  to  7  per  cent  are  mineral.  In 
them  has  been  found  stercorin  or  serolin,  which  is 
a  fatty  non-saponifiable  matter,  a  product  of  the 
decomposition  of  cholesterin,  also  a  white  crystalline 
substance,  called  e.wretin,  which  contains  sulphur,  and 
which  probably  effects  the  elimination  of  this  element 
from  the  system. 

Calcareous     and     magnesian     phosphates,     sodium 


260  AMMAL    CHEMISTRY. 

chloride,  a  small  quantity  of  silica,  i'atty  matter,  pro- 
ducts of  the  decomposition  of  the  acids  of  the  bile,  of 
the  epithelium,  and  the  tissues  of  the  vegetables  are 
also  found. 

The  use  of  iron  preparations  colours  the  excrements 
blackish- green  (iron  sulphide).  Calomel  gives  them 
a  light  green  colour.  If  they  contain  blood  the  colour 
will  be  dark  or  nearly  black. 

Cholera  excrements  contain  coagulated  albumen, 
cystoid  corpuscles,  and  chlorides  ;  common  salt  amount- 
ing sometimes  to  over  one-half  the  total  weight. 
In  dysentery  and  in  Blight's  disease  mucus  is  found. 
In  certain  excrements  the  presence  of  alloxan,  a  pro- 
duct of  the  oxidation  of  urea,  has  been  detected.  In 
typhoid  fever  they  are  mostly  iluid  and  alkaline.  On 
standing  a  viscous  mass  deposits,  containing  mucus,  food 
debris,  and  generally  crystals  of  magnesio-ammonium 
phosphate.  The  fluid  above  the  deposit  contains 
albumen,  various  soluble  salts  and  biliary  constituents. 
Addition  of  nitric  acid  produces  a  rose-red  coloration^ 
as  is  also  the  case  in  cholera  stools. 

Subjoined  are  the  results  of  two  analyses  of  human 
excrements,  which  from  the  inherent  difficulties  of  such 
investigations  cannot  be  regarded  as  exhibiting  their 
composition  with  very  complete  accuracy.  The  one  by 
Wehsarg  is  of  recent  date  : — 


SUMMARY    OF    DIGESTION.  267 

Berzelius.  Wehtsarg. 

Water      ....  75.30  73.300 

Biliary  salts     .         .         .0.90 

Mucus  and  biliary  resins  14.00 

Albumen          .         .         .0.90 

Extractive  matters    .          .     5.70 

Aqueous  extract        .          .  5.340 

Alcoholic     „  .         .  4.165 

Etherous     „  .         .  3.070 

Food  debris      .         .         .     7.00  8.300 

Mineral  salts    .          .          .      1.20 

Earthy  phosphates   .          .  1.095 

Total  salts  -'9.70  —       -  21.970 


INTESTINAL  CONCRETIONS. — These  contain  a  large 
proportion  of  fatty  matter,  a  substance  analogous  with 
iibrin,  calcium  phosphate,  and  sodium  chloride. 

The  name  bezoar  is  given  to  the  intestinal  concretions 
found  in  gazelles  and  goats.  They  are  formed  some- 
times of  an  organic  (lithiofellic;  acid,  sometimes  of 
calcium  and  ammonio-magnesium  phosphates. 


SUMMARY    OF    DIGESTION. 

To  recapitulate,  the  food  is  mechanically  divided  in 
the  mouth  by  the  action  of  the  tongue,  teeth,  and  the 
saliva,  which  latter  commences  the  transformation  of 
the  starchy  matter.  The  bolus  formed  passes  through 
the  ossophagus,  and  arrives  in  the  stomach,  where  the 


268  ANIMAL    CHEMISTRY. 

digestion  of  the  greater  part  of  the  nitrogenous  sub- 
stances is  effected  by  the  action  of  the  gastric  juice. 
The  majority  of  these  substances  having  become 
assimilable,  are  absorbed  by  the  walls  of  the  stomach, 
and  the  remainder  of  the  food  passes  into  the  duodenum. 
There  the  emulsion  of  the  fatty  matter  is  prepared,  and 
the  transformation  of  the  starch  into  glucose  effected 
by  the  action  of  the  bile,  pancreatic  juice,  etc.  This 
latter  fluid  also  effects  the  digestion  of  the  nitrogenous 
matters. 

The  food  as  modified  by  these  different  changes 
forms  chyme.  It  now  enters  the  jejunum,  and  moves 
forward  by  peristaltic  and  muscular  motions.  It  here 
receives  the  secretions,  which  complete  the  transforma- 
tion of  starch  into  sugar,  the  solution  of  the  albuminoid 
matter,  and  the  emulsion  of  the  fats.  •  The  chyliferous 
vessels  absorb  almost  exclusively  these  latter  substances, 
while  the  intestinal  veins  absorb  the  products  of  the 
transformation  of  the  fluids  and  albuminoid  bodies. 

The  absorption  of  the  liquid  products  of  digestion, 
and,  in  general,  the  absorption  of  liquids,  is  effected  by 
means  of  a  very  complex  mechanism. 

Diffusion  takes  the  principal  part  in  this  process ;  in 
fact  the  animal  membranes  are  lined  with  colloid  cells, 
through  which  diffusion  takes  place  with  great 
rapidity,  and  we  have  seen  that,  although  albuminoid 
substances  are  but  slightly  dialyzable  in  a  natural  state, 
they  become  quite  readily  so  on  being  transformed  into 
peptones. 


ABSORPTION.  26*9 


ABSORPTION. 

CHYLE,    LYMPH. 

A  VERY  considerable  quantity  of  lymph  and  chyle  is 
constantly  poured  into  the  blood.  These  fluids  are 
very  analogous  in  character  ;  they  have  a  circulatory 
movement ;  they  are  formed  of  a  liquid  (wrum]  in 
which  float  globules  capable  of  uniting  to  form  a  clot  or 
coayulum  ;  their  composition  is  also  similar,  there  being, 
in  fact,  little  difference,  except  in  the  proportion  of  their 
elements. 

The  chyle  is  a  lactescent  fluid  contained  in  special 
lymphatic  vessels,  into  which  it  passes  directly  from  the 
intestines ;  it  accumulates  in  the  mesenteric  glands, 
whence  it  passes  into  the  thoracic  duct.  It  may  be  ob- 
tained by  opening  this  duct  and  ligating  the  same  near 
where  it  enters  the  sub-clavian  vein.  However,  at  this 
point  it  has  already  undergone  elaboration,  and  is  mingled 
with  lymph  coming  from  different  points  in  the  body. 
Before  describing  the  chyle,  it  should  be  remarked  that 
the  knowledge  we  possess  of  this  fluid  is  based  chiefly 
upon  investigations  among  the  lower  animals. 


270  ANIMAL    CHEMISTRY. 

The  chyle  of  an  animal  deprived  of  food  is  yel- 
lowish ;  during  digestion,  especially  of  fatty  food,  it  is 
lactescent.  This  appearance  is  due  to  the  fatty  bodies 
present,  for  if  it  be  agitated  with  ether  it  loses  its 
milky  appearance.  It  has  a  feeble  odour,  a  slight 
taste,  and  its  reaction  is  faintly  alkaline. 

Chyle  contains  fibrin,  albumen,  and  urea.  The  pre- 
sence of  casein  is  suspected,  but  not  certain  ;  yet  the 
albumen  of  the  chyle  is  more  alkaline  than  ordinary 
albumen.  The  serum  of  chyle  becomes  covered  with 
a  film  during  evaporation  ;  it  coagulates  only  in  small 
flakes,  and  acetic  acid  precipitates  it  but  partially. 
Chyle  separated  from  the  body  coagulates  in  ten  to 
fifteen  minutes,  producing  a  clot  floating  in  an  albu- 
minous liquid  ;  this  coagulation  is  due  to  the  fibrin 
present. 

Lymph  is  a  colourless,  or  nearly  colourless,  liquid, 
It  reaction  is  alkaline,  which  appears  due,  like  the 
alkalinity  of  chyle,  to  a  matter  analogous  with  casein. 
It  contains  white  globules,  fibrin,  albumen,  urea,  fatty 
bodies,  and  salts,  which  are  chiefly  lactates. 

It  coagulates  after  being  exposed  to  the  air  for  a  few 
minutes,  producing  a  thin,  soft  clot,  coloured  red  by 
globules  of  blood. 

Robin  found  the  composition  of  human  lymph  and 
chyle  to  be,  in  1000  parts,  as  follows : — 


LYMPH,    CHYLE. 


271 


Lymph. 

Chyle. 

960  to  065 

900  to  990 

4  „  6 

5  „  7 

1  „  2 

not  determined 

0.23  „  0,50 


f 


0.80  to  3 
not  determined 
5  to  9 


"Water 

Sodium  chloride 

Sodium  carbonate 

Calcium  carbonate 

Alkaline  and  calcare-  £-0.05  ,,  2 

ous  phosphates        . ) 
Alkaline  sulphates     . 
Crystallized     organic '} 

principles       (urea,  (        3  „  8 

glucose) 
Fatty  bodies 
Albumen  . 
Fibrin 
Peptone    . 
Hematosin 


Wurtz  has  found  urea  in  the  lymph  of  various 
animals. 

The  above  analyses  do  not  wholly  agree  with  those  of 
other  chemists,  and  from  the  variable  character  of  these 
two  fluids,  and  the  inherent  difficulty  of  their  analysis, 
the  foregoing  figures  must  be  considered  as  giving  only 
an  approximative  idea  of  their  chemical  composition. 
The  variations  in  composition  are  greater,  however,  in 
chyle  than  in  lymph. 


2  „  9 

10  „  36 

33  „  60 

30  „  40 

1  „  5 

3  „  4 

3  „  4,5 

6  „  8 

0-6 

0.6 

272  ANIMAL    CHEMISTRY. 


BESPIRATION. 
THE  BLOOD. 

THE  blood  is  at  once  the  nutritive  and  the  purifying 
fluid  of  the  body.  From  one  part  of  the  body  it 
gathers  the  liquids  elaborated  by  digestion,  and  in 
another  it  takes  from  the  air  its  vital  principle,  oxygen, 
to  act  upon  these  liquids ;  also  it  collects  in  different 
parts  of  the  body  the  various  effete  products,  and 
carries  them  to  the  organs  destined  to  eliminate  them. 
The  blood  also  serves  to  distribute  heat  throughout  the 
body. 

It  circulates  incessantly  in  the  capillaries,  arteries, 
and  veins.  Arterial  blood  is  vermilion  red ;  venous 
blood  is  reddish  brown.  Its  odour  varies  somewhat 
with  the  species,  and  seems  more  marked  in  the  male 
than  in  the  female.  According  to  Barruel,  sulphuric 
acid  increases  its  odour. 

Its  taste  is  slightly  saline.  Its  density  varies  -be- 
tween 1.045  and  1.075.  It  has  an  alkaline  reaction, 
which  is  due  to  sodium  compounds. 

On  placing  under  the  microscope  a  very  thin  mem- 


THE    BLOOD.  273 

brane  like  the  foot  of  a  frog,  it  may  be  seen  that  tho 
blood  has  a  rapid  circulatory  movement,  and  that  it  ic 
formed  of  a  colourless  liquid  (plasma),  in  which  floats  an 
immense  number  of  globules,  drawn  with  it  in  the 
circulating  current.  The  globules  are  microscopic  in 
size,  the  majority  are  red,  yet  there  are  some  which 
are  colourless. 

A  great  many  analyses  of  blood  have  been  made. 
The  results  vary  according  to  the  physiological  con- 
ditions of  the  subject,  but  the  following  tables  give  an 
average  result: — 


Venous  Blood. 


Man. 

Woman. 

Water    . 

780.00 

791.00 

Grlobules 

140.00 

127.00 

Albumen 

69.00 

70.00 

Fibrin    .... 

2.20 

2.20 

Extractive     matter    and  ) 
salts    .                            .  j 
Serolin  . 

6.80 
0.02 

7.40 
0.02 

Fatty  matters  containing  ) 
phosphorus          .          <=  j 
Cholesterin 

0.49 
0.09 

0.46 

0.07 

Salts  of  fatty  acids 
Loss      .... 

1.00 
.40 

1.05 

.80 

1000.00 

1000.00 

274  -ANIMAL    CHEMISTRY. 

Salts  contained  in  1000  grammes  of  blood : — 

Sodium  chloride          .         .3.10  3.90 

Other  soluble  salts      .         .     2.50  2.90 

Iron  .  0.565         0.541 

Phosphates         .         .         .     0.330         0354 

(Becquerel  and  Rodier.) 

The  blood  on  leaving  the  body  loses  its  fluidity  in 
a  few  minutes,  becomes  viscous,  and  changes  into  a 
gelatinous  mass  which  gradually  contracts  and  forces 
out  drops  of  liquid,  serum,  which  unite  around  the 
coagulum  or  clot.  This  clot  gains  in  consistency,  and 
after  ten  to  thirty  hours  it  ceases  to  contract. 

Composition^ 

Serum  .  870 

Clot  130 


100C 

Each  of  the  'two  parts  composing  the  blood  has  the 
following  composition : — 


THE    BLOOD. 


275 


Serum 


(Fibrin     .... 
(Globules. 

/Water     .... 
Albumen 
Oxygen  . 
Nitrogen 
Carbon  dioxide 
Extractive  matter    . 
Phosphorated  fat 
Cholesterin      .          . 
Serolin    .... 
Margaric  acid. 
Sodium  chloride 
Potassium  chloride .         . 
Ammonium  chloride 
Sodium  carbonate    . 
Calcium  carbonate  . 
Magnesium  carbonate 
Calcium  phosphate  . 
Sodium  phosphate  . 
Magnesium  phosphate 
Potassium  phosphate 
Sodium  lactate 
Salts  of  fixed  fatty  acids  . 
Salts  of  volatile  fatty  acids 
Yellow  colouring  matter. 


3 
127 


}l30 

790 

70 


10 


1000 


(Dumas). 


276  ANIMAL    CHEMISTRY. 

Many  other  substances  also  exist  in  the  blood.  We 
may  say,  in  a  general  way,  that  it  contains  most  of  the 
immediate  principles  which  compose  the  tissues  and 
liquids  of  the  body. 

COAGULATION  OF  THE  BLOOD — SERUM. — The  blood,. 
we  have  said,  coagulates  on  being  removed  from  the 
body.  This  coagulation  seems  to  be  due  to  the  fibrin ,. 
for  if  the  blood  be  beaten  with  twigs,  the  fibrin  is  seen 
to  attach  itself  to  the  branches,  and  the  blood  has  lost 
its  property  of  coagulating.  The  serum  of  the  coagulum 
is  not  therefore  identical  with  the  plasma. 

This  latter  contains  fibrin,  and  the  former  has  been 
freed  of  it.  The  fibrin  imprisons  the  globules  of  the 
blood,  and  these  together  form  the  coagulum. 

Coagulation  is  not  due  to  the  fact  that  the  blood 
remains  at  rest  on  leaving  the  body  of  the  animal,  or 
because  it  becomes  cooled,  for  by  keeping  the  blood  in 
motion  and  maintaining  the  temperature  of  the  body, 
solidification  is  not  arrested.  It  is  not  due  to  the 
presence  of  air,  as  coagulation  takes  place  in  other 
gases  and  in  a  vacuum.  Acids  coagulate  blood.  The 
rapidity  of  coagulation  varies  from  a  few  minutes 
to  several  hours.  It  is  slower  in  the  blood  of  the 
vigorous  than  in  that  of  weak  persons.  It  is  accelerated 
by  raising  the  temperature  from  80°  to  48°. 

It  is  retarded  several  hours  by  lowering  the  tempera- 
ture to  0°.  The  addition  of  albumen,  sugar,  and 
solution  of  alkaline  salts  produces  the  same  effect,  and 
coagulation  is  even  arrested  by  concentrated  solutions 
of  certain  salts,  especially  sodium  sulphate. 

If  pulverized  sodium  chloride  be  added  to  this  liquid 


COAGULATION    OF    THE    BLOOD — SERUM.  277 

it  furnishes  flakes  of  an  albuminoid  substance,  which, 
according  to  Dennis,  is  different  from  albumen  and 
fibrin.  He  has  given  it  the  name  ofplasmin. 

It  is  very  soluble  in  water,  and  is  easily  decomposed 
into  soluble  and  insoluble  fibrin,  which,  according  to 
this  chemist,  is  the  cause  of  coagulation. 

Yirchow  and  Schmidt  regard  fibrin  as  produced  by 
the  combination  of  two  albuminoid  principles  of  the 
blood,  the  fibrino-plmiia  substance  or  paraglobuline  and 
fibrinogen  or  metaglobuline,  at  the  moment  when  the 
blood  is  removed  from  the  body. 

These  two  bodies  may  be  obtained  by  passing  a 
current  of  carbon  dioxide  through  plasma,  diluted  with 
ten  times  its  volume  of  water  at  0°.  The  fibrino- 
plastic  substance  is  immediately  precipitated  in  white 
flakes,  which  are  collected  on  a  filter  and  washed  with 
water,  charged  with  carbon  dioxide,  as  aerated  water 
dissolves  it.  The  stream  of  carbon  dioxide  is  now 
allowed  to  pass  through  the  liquor  for  a  long  time.  At 
first  an  abundant  foam  is  formed,  then  the  fibrogene 
separates  out  as  a  glutinous  mass. 

If  these  two  substances  are  separately  dissolved  in 
water  which  is  slightly  alkaline,  and  are  then  mixed,  a 
gelatinous  matter  separates  out  which  soon  forms  into 
filaments,  analogous  in  appearance  to  fibrin. 

According  to  Schmidt  these  two  substances  require 
for  their  action  the  presence  of  a  ferment,  which  is  not 
developed  in  blood  during  circulation,  but  which  is 
produced  as  soon  as  the  blood  is  removed  from  the 
body;  this  ferment  has  not  been  isolated — whence 
is  it  derived  ? 


278  ANIMAL    CHEMISTRY. 

According  to  others,  the  fibrin  is  already  formed  and 
solid  in  the  blood,  and  coagulation  is  simply  the  result 
of  the  aggregation  of  these  solid  particles.  Supposing 
it  to  be  proved  that  the  fibrin  exists  in  a  solid  state  in 
the  blood,  it  yet  remains  to  determine  the  cause  of  this 
aggregation  in  air. 

It  has  been  said  that  the  fibrin  surrounds  or  exists 
in  the  globules  ;  since,  however,  we  can  separate  the 
globules  and  still  have  a  coaguiable  plasma,  this 
hypothesis  is  not  admissible. 

Smee  considers  fibrin  as  oxidized  albumen.  But  how 
can  it  be  supposed  that  this  oxidation  takes  place  in  a 
few  seconds  ? 

Notwithstanding  all  that  has  been  written  concerning 
the  probable  cause  of  the  coagulation  of  the  blood,  it 
must  be  confessed  that  the  causes  thus  far  assigned  are 
not  wholly  satisfactory.  They  are,  for  the  most  part, 
mere  hypotheses. 

Serum  is  chiefly  a  solution  of  albumen.  But  this 
albumen  is  found  in  different  states,  free,  and  combined 
with  soda ;  also,  in  the  analyses  above  cited,  the  albu- 
minoid substances  (fibrogene  and  fibrino-plastic  sub- 
stance,) which  are  precipitated  by  carbon  dioxide,  have 
been  considered  as  albumen. 

E.  Mathieu  and  V.  Urbain  (9-79,  665  and  698) 
seem  to  have  established,  though  disputed  by  A. 
Gautier  (9-83-277),  that  the  coagulation  of  blood  is 
caused  by  the  carbon  dioxide,  which,  when  blood  is 
exposed  to  the  air,  is  expelled  from  the  blood  globules,, 
in  which  it  is  contained  during  life,  by  the  oxygen  of 


SERUM.  279 

the  air.  Hence  it  is  clear  why  alkalies  and  ammonium 
hydrate,  as  well  as  concentrated  solutions  of  certain 
salts  which  absorb  carbon  dioxide,  prevent  the  coagu- 
lation of  blood. 

Venous  serum  contains  somewhat  more  water  than 
that  of  the  arteries,  the  serum  of  women  containing, 
according  to  C.  Schmidt,  more  water  than  that  of  men. 
The  proportion  of  water  increases  in  most  diseases ; 
the  reverse  is  seldom  observed  except  in  certain  fevers 
and  in  cholera. 

The  abundance  of  albumen  in  the  serum  and  in  the 
blood  in  general  proves  that  this  substance  is  the  prin- 
cipal constituent  of  the  albuminoid  fluids  and  nitro- 
genous tissues  of  the  body.  Its  proportion  ranges 
between  63  and  70  in  1000  parts ;  it  increases  at  the 
moment  of  digestion.  Venous  blood  contains  more 
albumen  than  arterial  blood.  Its  quantity  generally 
diminishes  in  disease  ;  yet  it  increases,  as  does  the 
fibrin  from  other  causes,  in  inflammatory  fevers. 

The  fatty  bodies  of  the  serum  are  often  crystallizable, 
and  it  was  a  mixture  of  these  substances  which  was 
formerly  called  seroline.  There  is  a  small  quantity  of 
olein  and  oleic  acid  in  the  serum.  There  is  also 
found  in  it  stearin,  margarin,  the  two  corresponding 
acids,  and  cholesterin.  The  venous  blood  contains  more 
of  this  last  body  than  the  arterial  blood  ;  the  blood  of 
the  vena  porta  contains  more  than  that  of  any  other 
vessel. 

The  amount  of  fatty  bodies  increases  during  diges- 
tion. They  diminish  in  general  during  disease,  with 


.280  ANIMAL    CHEMISTRY. 

the  exception  of  cholesterin,  which  often  increases. 
The  blood  of  women  contains  a  little  more  than  that 
of  men. 

Grlucose  always  exists  in  the  serum ;  its  proportion  is 
very  small ;  it  increases  during  digestion  if  the  food  is 
very  starchy.  The  blood  of  the  hepatic  veins  contains 
a  considerable  proportion  of  this  substance,  while  the 
blood  of  the  vena  porta  hardly  contains  any  whatever. 
The  blood  of  diabetic  persons  scarcely  furnishes  0.05 
per  cent  ;  normal  blood  contains  at  the  most  0.0020 
per  cent. 

The  blood  which  is  most  rich  in  salts  is  that  of  the 
vena  porta ;  arterial  blood  in  general  contains  more 
than  venous  blood. 

A  considerable  diminution  in  the  quantity  of 
sodium  chloride  in  food  affects  health  seriously. 

Many  other  substances  have  been  found  in  the 
serum.  Some  are  constantly  met  with ;  these  are 
urea,  uric  acid,  hippuric  acid,  creatin,  creatinin,  casein, 
acetic  acid,  dextrin,  and  glucose,  the  peptones,  sodium 
and  potassium  chlorides,  sodium  carbonate  and  phos- 
phate, sodium  and  potassium  sulphates.  Neither 
glycocol,  leucin,  taurin,  nor  tyrosin  has  been  found. 

Prevost  and  Dumas  detected  the  presence  of  urea 
in  the  blood  after  the  suppression  of  the  urinary 
secretion.  The  existence  of  this  body  in  the  blood 
has  been  proved  by  Bechamp  and  other  experimenters. 
According  to  Picard,  normal  blood  contains  0.017 
of  urea ;  twice  as  much  is  found  in  the  renal  artery 
as  in  the  renal  vein. 


THE    COAGULUM.  281 

Casein  exists  principally  in  the  blood  of  pregnant 
women,  nurses,  and  nurslings. 

In  leucocythsBmia  the  blood  contains  gelatin,  hypo- 
xanthin,  lactic  and  formic  acids  i  biliary  acids  in 
diseases  of  the  liver,  ammonium  carbonate  in  persons 
having  cholera. 

THE  COAGULUM — crassamentum  or  clot — is  red  and 
somewhat  elastic.  It  is  formed  principally  of  fibrin 
and  globules,  and  incloses  about  one-fifth  of  its 
volume  of  serum.  It  seems  to  form  more  rapidly  in 
the  blood  of  a  child  than  in  that  of  an  adult,  in 
that  of  women  sooner  than  in  that  of  men  ;  its  com- 
pactness is  in  inverse  proportion  to  the  rapidity  of 
its  formation. 

In  some  pathological  states  the  separation  of  the  clot 
and  serum  does  not  take  place,  and  a  gelatinous  mass 
remains.  In  others  the  blood  is  rich  in  fibrin,  and  a 
whitish  matter  called  "  buff,"  or  buify  coat,  is  observed 
on  the  surface,  which  is  fibrin  nearly  free  from 
globules. 

On  agitating  coagulum  in  a  bag  placed  in  a  stream 
of  water  the  globules  and  other  proximate  principles, 
with  the  exception  of  the  fibrin,  are  carried  away  by 
the  water,  and  the  latter  remains  in  the  cloth  in  the 
form  of  greyish  filaments. 

GLOBULES.  —Blood  globules  may  be  obtained  by 
receiving  fresh  blood  in  a  saturated  solution  of  sodiimi 
sulphate,  then  filtering  ;  the  globules  remain  on  the 
filter  mingled  with  the  solution  of  the  salts. 

The    red    globules  of    the   blood  of   mammalia   are 


282  ANIMAL    CHEMISTRY 

minute  circular  disks,  slightly  thickened  at  the  margin. 
It  is  generally  admitted  that  they  are  formed  of  a 
colourless  membrane  ;  they  would,  therefore,  be  verit- 
able cells.  Yet  some  observers  regard  them  as  an 
agglomerated  gelatinous  substance  destitute  of  exterior 
membrane.  This  latter  view  is  not  probable,  for  on 
placing  a  drop  of  blood  on  the  slide  of  a  microscope 
and  adding  a  little  water  the  globules  are  seen  to 
swell,  also  the  margius  become  yellow  in  contact  with 
a  solution  of  iodine. 

According  to  Be  champ  and  Estor,  there  exists  in 
the  blood  on  leaving  the  body  an  immense  number 
of  movable  granulations  of  extreme  minuteness,  capable 
of  development,  of  uniting  and  even  of  changing  into 
bacteria  and  bacterides.  These  microscopic  beings — 
called  microcosms — are  said  to  form  the  globules  by 
their  aggregation.(?) 

These  savants  affirm  that  they  have  seen  them  form 
new  cells,  and  that  the  blood- globules  in  the  body  are- 
the  result  of  the  activity  of  the  microcosms.  The 
blood-globules  in  fishes,  reptiles,  and  birds  have  an 
elliptic  form. 

Milne-Edwards  has  shown  that  no  connection  exists 
between  the  size  of  animals  and  the  size  of  their 
blood-globules,  but  that  they  are  smaller  as  the  organ- 
ism is  more  perfect  and  respiration  more  active. 

Globules  have  a  greater  density  than  serum.  Placed 
in  contact  with  water  they  absorb  the  same,  swell,  and 
become  spherical.  At  the  same  time  a  quantity  of  the 
colouring  liquid  of  the  globules  is  extravasated  and 


GLOBULES.  283 

colours  the  water.  Change  of  form  exerts  a  great 
influence  upon  their  colour.  On  swelling,  they  take 
on  a  darker  tint.  On  losing  water  they  become  clear 
and  red ;  this  takes  place  when  they  come  in  contact 
with  sugar  and  alkaline  liquids.  The  globules  cannot, 
therefore,  be  collected  on  a  filter  and  washed  with 
water  without  becoming  altered.  A  solution  of  sodium 
sulphate  of  18°  Baume  does  not  attack  them,  and  if  a 
mixture  of  one  volume  of  blood  and  two  volumes  of 
this  solution  be  thrown  upon  a  filter,  they  may  be  sepa- 
rated from  the  serum  without  being  destroyed. 

This  result  is  better  obtained  by  adding  to  defibrinated 
blood  ten  times  its  volume  of  a  concentrated  solution  of 
common  salt ;  the  globules  are  precipitated,  and  may 
be  washed  with  salt  water. 

Besides  red  globules  there  exist  in  the  blood  white 
corpuscles ;  their  number  is  much  smaller  (about  1  in 
400).  There  appear  to  be  two  kinds. 

The  most  abundant,  the  plasmic,  lymphatic,  and 
fibrinou*  globules,  have  a  spherical  form.  Their  border 
is  very  well  defined ;  they  contain  a  viscid  matter  in 
which  float  little  nuclei,  which  refract  light  strongly. 
They  are  larger  than  the  red  globules  (diameter =0.01 13 
millimetre),  also  lighter  than  these  latter. 

They  may  be  distinguished  from  the  coloured 
globules  by  their  different  reactions.  Water  distends 
without  destroying  them,  and  dissolves  them  only  after 
a  long  time.  Acetic  acid  simply  causes  them  to 
contract. 


284  ANIMAL    CHEMISTRY. 

These  globules  are  not,  like  the  preceding  ones, 
specially  characteristic  of  the  blood,  for  they  are  found 
in  most  of  the  other  fluids  of  the  system. 

The  name  globulines  has  been  given  to  certain  white 
corpuscles,  not  numerous,  whose  diameter  is  about  -.^-^ 
of  a  millimetre.  They  are  small  spherical  nuclei, 
which  are  probably  derived  from  the  chyle. 

The  number  of  globules  in  a  cubic  millimetre  of 
blood  has  been  estimated  at  four  to  five  millions. 


ANALYSIS  OF  DRIED  GLOBULES. 

Human  Blood  of  a 

blood.  dog. 

Hsemoglobin         .         .       86.79  8(5.50 

Albuminoid  matter        .       12.24  12.55 

Lecithin  .         .         0.72  0.59 

Cholesterin    ...  .25  0.36 

(Hoppe-Seyler). 

The  albuminoid  matters  appear  to  be  constituted 
chiefly,  if  not  wholly,  of  fibrino-plastic  substance. 

Red  globules  treated  with  water  become  spherical 
and  distended,  the  colouring  matter  and  other  elements 
pass  into  the  water,  and  there  remains  a  gelatinous 
mass  of  a  pale  tint  called  stroma,  which  is  formed 
chiefly  of  albuminoid  substances. 

HJEMOGI,OHIN.  —  This  substance  is  prepared  by 
mixing  defibrinated  blood  with  an  equal  volume  of 


HAEMOGLOBIN.  285 

water,  and  adding  to  this  liquid  one-fourth  its  volume 
of  80  per  cent,  alcohol ;  this  mixture  is  allowed  to  stand 
twenty -four  hours  exposed  to  a  temperature  of  0°. 

Crystals  then  form  in  the  liquid,  which  are  pressed 
out  on  a  filter  and  purified  by  re-dissolving  in  water  and 
re-precipitating  by  adding  to  the  solution  one-fourth 
its  volume  of  alcohol  and  exposing  to  a  temperature 
below  0°. 

It  may  be  easily  obtained  in  an  impure  state  by 
adding  ether,  drop  by  drop,  to  defibrinated  blood.  The 
colour  of  the  blood  darkens  on  account  of  the  destruc- 
tion of  the  globules,  and  the  liquid  deposits  crystals  on 
exposure  to  a  low  temperature.  This  substance  is  also 
known  as  hcematocrystattin. 

The  haemoglobin  of  human  blood  forms  regular  rec- 
tangular prisms  ;  the  same  is  true  of  that  of  the  dog,  cat, 
horse,  and  lion.  That  of  guinea-pigs  and  mice  crystal- 
lizes in  tetrahedrons,  and  that  of  squirrels  in  hexagons. 

It  is  insoluble  in  absolute  alcohol,  ether,  chloroform, 
carbon  bisulphide,  and  essential  oils.  Acids  decompose 
it  without  dissolving.  Alkalies  dissolve  it  by  altering 
its  nature.  It  has  a  slightly  acid  reaction.  It  may  be 
preserved  after  having  been  dried  at  a  low  temperature. 
In  aqueous  solutions  it  is  slowly  destroyed  at  ordinary 
temperatures,  and  instantly  at  100°.  It  absorbs  oxygen 
at  ordinary  temperatures,  one  gramme  of  haemoglobin 
dried  at  0°  absorbing  more  than  I  c.c.  In  a  vacuum 
nearly  the  whole  of  this  gas  again  escapes.  Hemoglobin 
may  therefore  be  considered  as  that  constituent  of  the 
globxiles  which  fixes  oxj^gen. 


286  ANIMAL    CHEMISTRY. 

Haemoglobin  contains,  besides  carbon,  hydrogen, 
oxygen,  and  nitrogen,  small  quantities  of  sulphur  and 
phosphorus,  and  about  0.5  per  cent,  of  iron. 

HJSMATIN — H^EMIN. — An  aqueous  solution  of  haemo- 
globin heated  to  about  75°  or  80°  is  decomposed  into 
another  colouring  matter,  haematin,  and  an  albuminoid 
matter  which  coagulates.  This  decomposition  takes 
place  gradually  at  ordinary  temperatures,  in  presence 
of  acids  or  alkalies  in  solution.  Haematin  represents 
only  about  four  per  cent,  by  weight  of  haemoglobin. 

If  a  small  quantity  of  sodium  chloride  and  strong 
acetic  acid  is  added  to  haemoglobin  or  blood,  and  after 
having  heated  this  mixture  over  a  water-bath,  it  is 
allowed  to  slowly  cool,  hydrochlorate  of  haematin 
(haemin)  is  precipitated  in  rhomboidal  crystals  of  a  brown 
colour  ;  this  is  also  a  characteristic  test  in  medico-legal 
investigations.  Yirchow,  also  Robin,  have  designated 
as  hcBmatoidin  a  crystalline  matter,  containing  neither 
iron,  sulphur,  nor  phosphorus,  aod  which  results  from 
the  destruction  of  haematin  in  sanguinary  effusions. 
This  body  is,  however,  now  generally  recognized  as 
bilirubin. 

Haemoglobin  forms  with  carbonic  oxide  a  crystalline 
compound,  which  may  be  prepared  in  the  same  manner 
as  haemoglobin,  by  employing  blood  previously 
agitated  with  carbon  oxide.  These  crystals  have  the 
same  form  as  the  haemoglobulin. 

F.  Hoppe-Seyler  (60-1874-1065)  has  lately  care- 
fully investigated  the  colouring  matter  prepared  from 
hiematin,  by  reducing  substances,  and  proved  its 


IRON    IN    THE    BLOOD.  287 

identity  with  the  urobiUn  of  Jaffe  (36-1869-815),  and 
the  hydrobilirubin  of  Maly  (36-1872-836). 

It  should  be  observed  that  Thudichum  and  Kingzett 
have  quite  recently  (32-' 76-255)  made  an  analysis  of 
haemin,  and  finding  the  same  to  contain  7.65  per  cent, 
iron,  3.02  chlorine,  and  0.60  phosphorus,  have  come 
to  the  conclusion  that  haemin  is  in  reality  a  substance 
consisting  of  haematin,  chlorhydrate  of  haematin,  and  a 
crystalline  compound  containing  phosphorus,  which 
they  regard  as  identical  with  my  elm,  a  body  claimed  by 
Virchow  as  existing  in  the  brain. 

C.  Husson  (9-81-477)  states  that  crystalline  com- 
pounds may  be  formed  between  haematin  and  phenol, 
oxalic  acid,  valerianic  acid,  tartaric  acid,  citric  acid,  and 
silica. 

Haemoglobin  forms  crystalline  compounds  with 
nitrogen  dioxide  and  cyanhydric  acid. 

Red  globules  are  not  attacked  by  albumen,  gum,  or 
sugar  solutions,  carbon  dioxide,  or  neutral  salts  of  the 
alkaline  metals.  Alum,  chlorine,  sulphuric  acid,  and 
nitric  acid  cause  them  to  contract ;  water,  organic,  and 
phosphoric  acids,  and  alkaline  solutions  dissolve  them. 

Milne-Edwards  (9-79-1 268)  remarks  that  the  respira- 
tory power  of  the  blood  depends  upon  the  number  of 
red  blood- corpuscles  present. 

IRON  IN  THE  BLOOD. — Boussingault  determined  this 
metal  among  the  elements  of  cow's  blood.  In  100 
parts  he  obtained : 


288  ANIMAL    CHEMISTRY. 

Total  Mineral 
Substances.  fron. 

Dry  fibrin  .     2.151  grammes     0.0466  grammes 

Dry  albumen      .     8.715       „           '  0.0863     „ 
Dry  globules       .     1.325       „  0.3500     „ 

The  colouring  matter  of  the  blood  owes  its  colour 
mainly  to  the  large  proportion  of  iron  in  the  globules, 
which,  dried,  gives : 

10.750  per  cent,  ash,  containing 
9.043         „         ferric  oxide, 
1.707         „         other  mineral  substances, 

formed  almost  entirely  of  lime  and  phosphoric  acid. 

P.  Picard  (9-79-1266)  found  the  proportion  of 
iron  in  the  blood  of  dogs  to  be  quite  variable  and  pro- 
portional to  the  amount  of  oxygen  the  blood  was 
capable  of  absorbing.  In  his  investigations  regarding 
the  amount  of  iron  in  the  human  body,  the  spleen  gave 
higher  proportions  than  any  other  organ. 

Jolly  has  very  lately  (61 -'78)  made  analyses  that 
appear  to  show  that  the  iron  in  blood  exists  as  ferrous 
phosphate. 

GASES    OF    THE    BLOOD. 

Magnus  was  the  first  to  make,  in  1837,  an  extended 
study  of  the  gases  contained  in  the  blood.  A  flask  con- 
taining blood  was  agitated  violently,  in  order  to  coagu- 
late the  fibrin.  The  defibrinated  blood  was  transferred 


GASES   OF   THE    BLOOD.  289 

into  a  bell  glass,  filled  with  mercury.  He  obtained 
the  following  composition  of  the  gases  liberated  : — 

Venous  Blood.  Arterial  Blood. 

Carbon  dioxide         .        .     71.6  62.3 

Oxygen  ....     15.3  23.2 

Nitrogen         .         .         .     13.1  14.5 


100.0  100.0 

His  methods  of  collecting  the  mixed  gases  were  not, 
however,  complete,  and  later  analyses  may  be  regarded 
as  more  reliable. 

C.  Bernard  determined  the  amount  of  oxygen  in  the 
blood,  profiting  from  a  fact  discovered  by  him  that 
carbon  oxide  displaces  the  oxygen.  The  blood  is  taken 
directly  from  the  body  by  a  syringe,  and  immediately 
introduced  into  a  graduated  tube  half-filled  with 
carbon  oxide.  This  is  agitated,  and  kept  at  a  tem- 
perature of  40°,  after  which  the  amount  of  oxygen  in 
the  gas  is  determined. 

Venous  and  arterial  blood  dissolve  variable  quanti- 
ties of  oxygen.  100  volumes  of  blood  from  a  young 
dog  contained  : 

In  the  left  ventricle,  23.0  vol.  of  oxygen.     Animal 

fasting. 
In  the  left  ventricle,   17.6  vol.  of  oxygen.     Animal 

digesting. 
In  the  right  ventricle,  10.0  vol.  of  oxygen.     Animal 

fasting. 


290  ANIMAL    CHEMISTRY. 

In  the  right  ventricle,  10.2  vol.  of  oxygen.     Animal 

digesting. 

The  gases  from  the  blood  of  a  dog  gave,  in  100 
parts: 

Nitrogen.     Oxygen.     Carbon        Carbon  di- 

dioxide.   oxide  combined. 

Arterial  fl.61  20.05  348  traces. 

blood  12.30  22.2  35.3  0.88 

Venous  rl.32  12.1  43.5  4.40 

blood  11.64  11.6  42.8  5.30 

When  venous  blood  is  agitated  with  oxygen  it  takes 
on  the  red  colour  of  arterial  blood.  ?  If,  on  the  contrary, 
arterial  blood  be  agitated  with  carbon  dioxide,  hydrogen, 
or  nitrogen,  it  assumes  the  dark  brown  tint  of  venous 
blood. 

P.  Bert  (9-80-733)  found,  in  his  investigations  upon 
the  power  of  blood  to  absorb  oxygen  at  different  pres- 
sures, that  a  compound  of  haemoglobin  with  oxygen 
(oxyluvmoglobin,)  is  obtained  when  blood  is  agitated 
with  air  at  ordinary  pressure.  Increase  of  pressure  in- 
creases the  proportion  of  oxygen  in  this  compound  ;  it 
also  remains  constant  until  the  pressure  is  lowered  to 
one-eighth  of  an  atmosphere  at  16°,  but  at  the  tem- 
perature of  the  bodies  of  mammalia  it  decomposes  as 
the  pressure  is  further  removed. 

The  blood  on  leaving  the  lungs  does  not  contain  as 
much  oxygen  as  it  is  capable  of  absorbing.  Grrehant 
has  found  that  in  agitating  blood  with  oxygen  the 
quantity  which  it  is  capable  of  absorbing  is  to  the 


ACTION    OF    OZONE    ON    THE    BLOOD.  291 

quantity  ordinarily  found  in  it  as  about  26  to  16.  But 
there  is  a  great  difference  in  this  regard  between  indi- 
viduals, their  state  of  health,  etc. 

The  opinion  has  been  expressed  that  the  blood  con- 
tains ozone,  but  this  cannot  be  admitted,  as  the  blood, 
like  all  organic  matter,  destroys  ozone.  It  is  'only 
necessary  to  agitate  blood  in  a  vessel  with  ozone  to 
obtain  proof  that  these  two  bodies  are  incompatible, 
for  the  odour  of  ozone  disappears  immediately. 

J.  Dogiel  (75-24—431)  states,,  as  the  result  of  hia 
recent  researches  regarding  the  action  of  ozone  upon 
the  blood,  that  the  action  of  the  ozone  is  chiefly  upon 
the  red  blood-corpuscles ;  their  colouring  matter  is 
expelled,  and  they  become  darker  within  fifteen  minutes. 
After  this  change  alcohol,  ether,  or  chloroform  pro- 
duces no  separation  of  crystals  of  haemoglobin.  Upon 
passing  ozone  through  defibrinated  blood  for  a  long 
time,  flakes  separate  out,  which,  after  washing  with 
water,  are  not  to  be  distinguished  from  fibrin.  By 
continued  action  of  ozone  blood  becomes  first  of  a  dirty, 
yellowish-green  colour,  and,  finally,  colourless.  Hnema- 
tin  is  likewise  rendered  colourless  by  ozone.  Blood 
poisoned  with  carbon  oxide  attains  in  a  short  time  the 
properties  of  normal  blood  on  exposure  to  the  action  of 
ozone,  carbon  dioxide  being  given  off.  Blood  contain- 
ing carbon  oxide  is  discoloured  less  quickly  than 
normal  blood,  and  does  not  so  quickly  lose  its  property 
of  depositing  crystals  of  haemoglobin.  The  change  of 
the  blood  corpuscles  produced  by  ozone  should  not  be 
•confounded  with  the  change  produced  by  carbon  dioxide. 


292 


ANIMAL    CHEMISTRY. 


Carbon  oxide  displaces  the  oxygen  of  the  blood, 
and  is  very  deleterious  when  inhaled. 

Chlorine  coagulates  blood,  removes  the  iron  which 
enters  into  the  composition  of  its  colouring  matter,  and 
subsequently  destroys  the  organic  matter.  The  iron  is 
changed  into  ferric  chloride,  capable  of  being  detected 
with  reagents. 

Arsenide  of  hydrogen  completely  changes  the  nature 
of  blood,  which  assumes  the  colour  of  ochre. 

Defibrinated  blood  becomes  brown  and  then  dark 
green  under  the  action  of  hydrogen  sulphide ;  the 
colouring  matter  is  attacked  and  the  globules  de- 
stroyed. 

Certain  neutral  salts,  the  alkaline  sulphates,  phos- 
phates, and  nitrates,  redden  the  blood  in  the  same 
manner  as  oxygen. 

Ore  (9-31-833,  990)  asserts  that  acetic  acid,  sul- 
phuric acid,  nitric  acid,  hydrochloric  acid,  phosphoric 
acid,  or  alcohol  after  being  diluted  with  water,  may  be 
injected  into  the  blood-vessels  of  a  living  animal  with- 
out producing  coagulation  of  the  blood. 


DIFFERENCES    BETWEEN    ARTERIAL    AND    VENOUS 
BLOOD. 

We  have   incidentally   noticed  these   differences  in 
studying  the  various  constituents  of  the  blood. 
Longet  sums  them  up  as  follows  : 


INDUSTRIAL    USES    OF    BLOOD. 


293 


Arterial  Blood. 

1st;  Vermilion  red. 

"2nd.  Rich  in  fibrin. 

3rd.       „     „  globules.  ? 

4th.       ,,     „  salts. 

oth.  Contains  about  30 
parts  of  oxygen  to  100 
of  carbon  dioxide. 

6th.  More  ooagulable. 

7th.  Less  abundant  in 
fatty  matters.  ? 

-8th.  Has  the  same  com- 
position in  all  parts 
of  the  arterial  system. 


Venous  Blood. 
1st.  Brown  red. 
2nd.  Rich  in  albumen.  ? 
3rd.    Has  less  water. 
4th.       „      „       extractive 

matters. 

5th.  Contains  about  22 
parts  of  oxygen  to 
100  of  carbon  dioxide. 
6th.  Less  coagulable. 
7th.  Grlobules  more  abun- 
dant in  fatty  matter.  ? 
8th.  Has  a  different  com- 
position in  different 
parts  of  the  venal 
system. 

We  have  indicated  by  ?  such  items  in  Longet's  tabula- 
tion as  are  doubtful,  or  at  least  are  not  constant. 

INDUSTRIAL  USES  OF  BLOOD. —  Coagulated  blood 
serves  as  food  in  certain  countries,  as  Grermany,  Sweden, 
and  Italy.  Freshly  drawn  blood  is  highly  nutritious, 
and  not  unfrequently  used  by  emaciated  and  greatly 
enfeebled  invalids.  The  large  quantity  of  albumen 
contained  in  the  blood  and  the  property  which  albumen 
possesses  of  coagulating  on  heating,  causes  blood  to  be 
employed  in  sugar  refineries  for  the  clarification  of 
sugars. 


294  /VIMAL  CHEAT ISTRY. 


CHEMICAL   PATHOLOGY   OF   THE    BLOOD. 

SINCE  the  blood  circulates  throughout  the  entire 
body,  it  is  evident  that  diseases  which  manifest  them- 
selves at  any  point  necessarily  produce  modifications  in 
the  blood,  hence  it  may  be  asserted  that  an  examina- 
tion of  the  blood  furnishes  a  valuable  basis  of  dia- 
gnosis. Yet,  from  the  fact  that  only  blood  taken  from 
a  superficial  vein  can  be  experimented  with,  and  that 
the  blood  becomes  contaminated  in  its  passage  through 
the  body,  the  small  quantity,  therefore,  of  abnormal  or 
noxious  matter  is  often  found  to  be  too  slight  for  the 
determination  of  its  amount,  or  in  some  cases  even  for 
its  detection. 

The  chemical  facts  which  we  possess  in  regard  to  the 
variations  of  the  blood  in  different  diseases  are  few.  It 
is  only  known  that  in  such  and  such  states  there  is  a 
diminution  or  increase  of  this  or  that  principle.  We  are 
not  sufficiently  informed  as  to  the  genesis  of  these 
substances  to  be  able  to  decide,  whether  the  morbid 
condition  appertains  to  one  organ  rather  than  to  an- 
other, or  whether  the  disease  is  due  to  a  given  cause  or 
to  some  other. 

The  proximate  principles  of  the  blood  may  also 
seem  to  increase,  without  this  increase  being  either 
real  or  as  great  as  would  appear  :  this  may  be  due  to 
a  diminution  in  the  total  mass  of  blood. 


ANEMIA. 

PLETHORA.  —  Plethora  may  be  due  either  to  an 
increase  in  the  proportion  of  globules,  or  an  augmenta- 
tion in  the  volume  of  the  blood ;  therefore  we  distin- 
guish between  globular  and  sanguinary  plethora. 

In  the  former  the  globules  increase. 

In  sanguinary  plethora — that  is,  in  the  augmentation 
of  the  mass  of  the  blood — the  reverse  occurs,  as  the 
quantity  of  blood  may  increase  in  greater  proportion 
than  the  globules. 

ANAEMIA. — Here  also  there  may  be  either  diminution 
of  the  mass  of  the  globules  or  a  diminution  in  the  total 
amount  of  the  blood. 

In  the  first  case,  an  increase  of  water  and  fibrin  is 
noticed  in  the  blood,  and  often  the  number  of  colourless 
globules  increases.  The  clot  is  firm  and  often  produces 
"  buff." 

The  anaemic  state  occurs  when  the  body  does  not 
repair  the  losses  which  it  has  undergone ;  it  is  pro- 
duced during  growth,  at  the  time  of  puberty,  or  after 
diseases  which  impede  digestion.  Iron  and  its  prepa- 
rations have  a  very  favourable  influence  on  the  develop- 
ment of  globules. 

We  have  just  stated  that  certain  anaemic  conditions 
correspond  to  an  increase  of  colourless  globules.  The 
spleen  then  increases  in  size ;  the  blood  which  remains 
in  the  spleen  is  very  rich  in  white  globules,  contain- 
ing 1  to  49  of  the  coloured  globules.  The  blood  of 
the  splenic  vein  also  contains  large  numbers  of  these 
globules.  The  coagulum  of  the  blood  of  this  vein  is 


296  ANIMAL    CHEMISTRY. 

but  slightly  compact ;  the  serum  which  separates  there- 
from coagulates  after  a  short  time. 

The  following  hypothesis  based  upon  these  factr> 
has  been  proposed:  The  spleen  is  an  organ  which 
destroys  red  globules,  changing  them  into  white 
globules  which  are  carried  along  into  the  circulation 
and  afterwards  again  transformed  into  red  globules. 
These  views  are,  however,  not  regarded  as  established. 

LEUCOCYTHJEMIA  — This  name  is  given  to  a  morbid 
state  characterized  by  the  abundance  of  white  globules  : 
the  number  of  these  may  amount  to  one-fourth  and 
more  of  the  total  number  of  globules.  The  blood  is 
then  milky,  and  often  acid  from  the  formation  of  acetic 
or  lactic  acid. 

CHOLERA — TYPHOID  FEVER. — The  globules  assume 
irregular  forms,  and  unite  together  during  cholera  and 
typhus.  In  this  latter  disease,  and  in  tuberculosis  in 
its  advanced  stages,  the  blood  loses  its  property  of 
becoming  red  in  contact  with  oxygen,  since  this  gas 
no  longer  unites  with  the  globules.  The  blood  of 
typhus  patients  contains  ammonium  carbonate,  pro- 
duced by  the  transformation  of  urea,  and  it  is  probably 
this  compound  which  leads  to  the  alteration  of  the 
globules,  as  the  same  phenomenon  is  observed  when 
ammonia  is  introduced  into  the  blood. 

Ammonia  and  many  toxic  agents  attack  the  enve- 
lopes of  the  globules  ;  hence,  whenever  these  substances 
are  present  in  the  blood,  the  globules  become  ruptured, 
and  death  ensues  in  the  absence  of  prompt  antidotes. 

The  blood  is  thick,  and  resembles  gooseberry  jelly  in 


DISEASES    IN    WHICH    THE    FIBRIN    DIMINISHES.    297 

cholera  ;  globules,  as  well  as  albumen  and  extractive 
substances  abound.  The  serum  is  deficient,  is  dense, 
and  generally  poor  in  salts,  yet  the  potassa  compounds 
and  phosphates  increase.  As  the  urinary  secretion  is 
diminished  or  suppressed,  the  urea  increases  in  the 
blood,  and  there  is  produced  ammonium  carbonate. 

SCURVY. — The  change  in  the  blood  is  quite  marked 
in  this  morbid  state.  It  is  disorganized  on  account  of 
the  dissolution  of  the  globules,  and  the  diminution  of 
albumen  and  salts. 

ALBUMINURIA. — The  blood  does  not  seem  to  change 
in  the  amount  of  fibrin.  The  proportion  of  globules  and 
albumen  is  greatly  diminished. 

DROPSY. — The  globules  and  albumen  dimmish,  and 
the  serum  is  extravasated. 

INFLAMMATORY  DISEASES  — The  fibrin  increases  in 
these  affections,  iu  pleurisy,  pneumonia,  and  acute 
articular  rheumatism.  The  proportion  of  this  body, 
which,  in  normal  blood,  is  2  to  2.3,  rises  to  7.8  and 
even  9  parts  in  1000. 

The  fatty  matters  augment,  and  the  albumen  and 
globules  diminish  slightly. 

The  blood  is  charged  with  carbon  dioxide,  which 
fact  explains  the  retarding  of  the  coagulation,  as  a 
large  proportion  of  this  gas  prevents  coagulation. 

DISEASES  IN  WHICH  THE  FIBRIN  DIMINISHES. — When 
food  is  insufficient,  also  in  cases  of  syphilis,  in  prolonged 
suppuration,  in  typhoid  fever,  and  in  scurvy,  the  fibrin 
generally  diminishes,  or  loses  its  property  of  coagulating. 

The  coagulation  of  che  blood  is  very  slow  in  diseases 
of  the  respiratory  organs,  when  the  hematosis  is  in  com- 


298  ANIMAL    CHEMISTRY. 

plete,  and  after  death  by  syncope.  It  does  not.  oocur  in 
the  blood  of  persons  asphyxiated,  killed  by  lightning, 
or  poisoned  with  cyanhydric  acid,  narcotics,  hydrogen 
sulphide,  or  ammonia.  Usually  in  a  fatal*  result  there 
is  a  complete  destruction  of  the  globules.  In  this  case, 
oxygen  ceased  to  unite  with  the  blood,  and  the  serum 
becomes  coloured  The  blood  of  persons  who  have 
died  from  the  bite  of  a  serpent  coagulates  very 
rapidly.  It  should  be  remarked  that  a  decrease  in  the 
amount  of  fibrin  in  the  blood  does  not  always  occur  in 
the  cases  as  cited  above,  and,  indeed,  it  is  claimed  by 
Gorup-Besauez  (21-364)  that  in  no  disease  whatever  is 
there  uniformly  a  diminution  in  the  fibrin. 

VARIATION  IN  THE  ALBUM KN. — The  blood  becomes 
poor  in  albumen  under  a  great  many  circumstances :  after 
loss  of  blood,  prolonged  suppuration,  in  albuminuria  and 
dropsy,  in  malarial  fevers,  in  typhoid  fever,  and  scurvy. 

The  albumen  seems  to  diminish  in  proportion  as 
tho  fibrin  increases. 

VARIATIONS  IN  ALKALINITY.  —  Normal  blood  is 
alkaline  This  alkalinity  increases  in  typhoid  and 
putrid  fevers,  which  is  probably  due  to  the  formation  in 
the  blood  of  ammonium  carbonate  from  urea. 

The  blood  lias  been  known  to  become  acid  after  an 
abnormal  production  of  lactic  acid.  The  globules  are 
then  dissolved  by  this  body,  and  death  rapidly  ensues. 

The  alkalinity  seems  to  diminish  in  inflammatory 
diseases. 

VARIATIONS  IN  THE  FATTY  BODIES. — The  drinking 
of  large  quantities  of  fluids  augments  the  proportion  of 
the  fatty  bodies,  and  it  seems  certain  that  corpulent 


VARIATIONS    IN    SUGAR.  299 

persons  would  grow  thin  on  diminishing  the  quantity 
of  liquid  which  they  imbibe. 

The  fatty  matters  generally  augment  during  affec- 
tions of  the  liver,  in  phlegmasia,  Bright's  disease,  and 
in  the  first  stage  of  some  acute  diseases. 

Z.  Pupier  (9-80-1146)  has  lately  found  by  extended 
researches  that  the  use  of  sodium  bicarbonate  or 
alkaline  mineral  waters  tends  to  increase  the  number 
of  red  blood-corpuscles  both  in  man  and  animals. 

OTHER  VARIATIONS. — The  extractive  mutters  become 
abundant  in  puerperal  fever  and  scurvy. 

Claude  Bernard  recently  (9-83-407)  set  forth  the 
following,  based  upon  his  investigations  regarding  the 
quantity  of  sugar  in  the  blood. 

The  sugar  of  the  blood  is  soon  decomposed  on  the 
removal  of  the  latter  from  tne  body.  After  death  the 
sugar  also  rapidly  decomposes,  even  when  retained  ir 
the  blood-vessels.  The  presence  of  sugar  is  independent 
of  the  nature  of  the  food ;  in  the  arteries  it  is  uniform 
in  quantity,  while  in  the  veins,  except  in  the  hepatic, 
though  variable,  it  is  yet  less  than  in  the  arterial  system. 

The  amount  of  sugar  increases  in  diabetes. 

To  extract  the  sugar  of  the  blood,  the  latter  is  first 
defibrinated.  To  the  serum  is  added  its  triple  volume 
of  alcohol ;  the  coagulum  is  separated  and  washed  with 
water  containing  an  equal  volume  of  alcohol.  It  is 
now  evaporated  to  dryness,  and  the  residue  treated 
with  al'-ohol,  which  dissolves  the  sugar. 

V.  ?eltz  (9- SO- 553,  1338)  recently  ascertained  by 
his  investigations  upon  the  action  of  putrefying  blood 
upon  animals,  that  injection  of  the  same  into  a  vein  of 


300  ANIMAL    CHEMISTRY. 

an  animal  produced  septicaemia.  The  poisonous  pro- 
perties of  putrefied  blood  are  not  changed  by  passing 
air  through  the  same,  but  are  lessened  by  the  action  of 
pure  oxygen.  If  the  gases  of  the  blood  are  removed 
with  a  pump  and  the  blood  allowed  to  remain  in  a 
vacuum  for  some  time,  it  loses  its  poisonous  properties. 
Feltz  is  of  the  opinion  that  the  poisonous  body  is  a 
gas.  In  all  stages  of  putrefaction,  even  after  being 
dried  in  the  air,  blood  retains  the  property  of  produc- 
ing septicaemia. 

Uric  acicTis  sometimes  observed  to  increase  in  the  blood. 

The  blood  of  icterical  persons  contains  the  colouring 
matter  and  other  constituents  of  the  bile. 

V >'(>((  accumulates  in  the  blood  when  the  kidneys 
perform  their  functions  badly  ;  this  condition  is  'known 
by  the  name  oi'  urccmia.  The  urea  which  accumulates 
in  the  blood  is  partially  decomposed,  producing 
ammonium  carbonate. 

Von  Grorup  Besanez  (75-23-135)  found  in  the  blood 
of  a  man  suffering  with  atrophy  of  the  liver,  besides 
the  normal  constituents,  a  body  closely  related  to 
gluten,  but  very  different  in  its  optical  properties, 
hypoxanthin  in  not  inappreciable  quantity,  formic  acid, 
and  volatile  fatty  acids,  rich  in  carbon,  also  a  non- 
volatile strong  organic  acid,  soluble  in  water,  alcohol, 
and  ether,  which,  however,  is  not  lactic  acid.  Uric 
acid,  xanthiu,  leucin,  and  tyrosin  could  not  be  found. 

The  proportion  of  salts  diminishes  in  intermittent 
fevers,  scurvy,  Bright's  disease,  dysentery,  and  typhoid 
'tates.  It  augments  in  intermittent  fevers  and  cholera. 


RESPIRATION.  301 


BESPIRATION. 


The  atmosphere  penetrates  certain  special  organs, 
which  are  the  lungs  in  man,  brnnchia  in  fishes,  and 
trachea  in  insects.  There  is  thus  established  a  continual 
exchange  between  the  blood  and  the  air,  which  is  called 
respiration. 

The  oxygen  of  the  air  coming  in  contact  with  the 
membranous  walls  of  the  respiratory  organ,  which  are 
very  thin  and  very  permeable,  traverses  them  and 
penetrates  the  blood.  It  is  not  dissolved  in  the  serum 
of  this  liquid,  but  it  fastens  itself  upon  the  globules, 
and  forms  with  their  substance  a  very  unstable  combi- 
nation. Inversely,  the  carbon  dioxide  and  aqueous 
vapour  on  reaching  the  lungs  in  the  venous  blood 
escape  through  the  same  membranes,  and  are  exhaled 
i:i to  the  atmosphere  to  be  again  shortly  decomposed  by 
the  green  portions  of  plants. 

F 


ANIMAL    CHEMISTRY. 


THEORY  OF  RESPIRATION. 

DIFFERENT  methods  have  been  employed  for  studying 
the  phenomena  of  respiration.  Lavoisier  was  the  first 
to  solve  the  problem;  his  method,  which  has  since 
been  perfected  by  Regnault  and  Reiset,  consists  in 
placing  the  subject  to  be  experimented  upon  in  a  known 
volume  of  oxygen,  absorbing  the  carbon  dioxide  ex- 
haled and  renewing  the  oxygen,  in  a  continuous 
manner. 

A  second  method  consists  in  placing  the  subject  in  a 
confined  space  and  analyzing  this  air,  determining  the 
volume  of  gas  exhaled  at  each  expiration,  counting  the 
number  of  respirations  made  during  a  certain  time,  and 
analyzing  the  air  exhaled  during  this  time. 

By  this  method  absolute  results  cannot  be  obtained, 
as  nitrogen  is  also  exhaled  during  respiration,  and  time 
we  have  two  unknown  data :  the  weight  of  the  nitrogen 
exhaled,  and  that  of  the  oxygen  consumed  to  form 
water. 

Boussingault  made  use  of  an  indirect  method,  which 
consisted  in  feeding  the  animal  in  such  a  manner  that 
its  weight  remained  constant,  also  weighing  and  analyz- 
ing the  food,  as  well  as  the  excrements,  and  subtract- 
ing the  weight  of  the  latter  from  the  former. 

It  is  clear  that  the  difference  between  these  two 
weights  represents  what  had  been  lost  by  pulmonary 
;md  cutaneous  respiration. 


THEORY    OF    RESPIRATION.  303 

Boussingau.lt  experimented  on  horses,  cows,  and 
doves. 

The  quantity  of  oxygen  consumed  is  proportional  to 
the  energy  with  which  the  vital  functions  are  executed. 

Dumas,  experimenting  on  himself,  found  that  the 
absorption  of  oxygen  was  at  the  maximum  23  litres  or 
33  grammes  per  hour,  or  about  800  grammes  for  24 
hours ;  13  litres  of  carbon  dioxide  are  produced ;  the  air 
expired  contains  4  per  cent,  of  this  gas. 

Substantially,  the  amount  of  oxygen  consumed  varies 
between  ^0  and  25  litres  per  hour,  or  29  to  36  grammes 
for  an  adult  man  in  a  state  of  repose. 

We  are  indebted  to  Scharling,  Andral,  and  Gravarret, 
also  to  Pettenkoffer,  Regnault,  and  Reiset  for  important 
researches  on  respiration. 

The  apparatus  of  Scharling  consists  of  a  chamber  of 
one  cubic  metre  capacity,  made  absolutely  tight  by  a 
covering  of  sized  paper.  The  subject  is  placed  in  this 
for  half  an  hour  to  one  hour.  The  air  enters  the 
chamber  through  an  orifice  in  the  lower  portion,  and  is 
drawn  in  by  ft  water  aspirator.  The  products  of  respi- 
ration pass  into  a  series  of  flasks,  the  first  of  which 
contains  sulphuric  acid,  which  retains  the  moisture,  the 
remainder  containing  alkaline  substances  to  absorb  the 
carbon  dioxide  formed. 

.Two  important  objections  to  this  method  may  be 
stated.  The  air  is  not  sufficiently  renewed,  and  the 
chamber  is  too  small.  It  results,  therefore,  that  the  air 
of  the  box  becomes  charged  with  carbon  dioxide  and 
aqueous  vapour,  and  becomes  elevated  in  temperature 


304  ANIMAL    CHEMISTRY. 

in  an  unnatural  manner.  These  circumstances  exert  a. 
deleterious  influence  upon  respiration,  and  must  neces- 
sarily bring  about  abnormal  conditions. 

Scharling  found  that  in  the  respiration  of  a  man  34 
grammes  or  17  to  18  litres  of  carbon  dioxide  are  pro- 
per hour. 

Andral  and  Gavarret  took  special  care  not  to  effect 
any  modification  of  the  normal  conditions  of  respiration. 

A  mask  of  thin  copper,  the  edges  of  which  were 
furnished  with  a  cushion  of  caoutchouc  in  order  to 
prevent  any  escape  of  gas,  is  fixed  firmly  to  the  face  of 
the  subject,  which  it  covers  without  binding. 

This  mask  is  large  enough  to  receive  the  product  of 
an  entire  respiration,  and  opposite  the  eyes  it  is  pierced 
with  two  orifices  closed  with  glass. 

The  air  penetrates  the  mask  by  two  tubes,  which 
enter  the  mask  at  the  height  of  the  corners  of  the  lips. 
The  air  expired  does  not  pass  out  through  these  tubes, 
as  they  contain  two  little  balls  of  elder-pith,  which  serve 
as  valves.  The  air  escapes  through  an  opening  situated 
opposite  the  mouth,  and  enters  into  three  flasks,  from 
which  the  air  has  been  exhausted,  and  whose  capacity 
is  140  litres. 

The  chief  difficulty  consisted  in  regulating  the  open- 
ing of  the  cock  which  separates  the  flasks  from  the 
opening  in  the  mask,  in  such  a  manner  that  respiration 
could  take  place  easily,  both  for  inspiration  and  expira- 
tion. 

The  operation  lasted  from  eight  to  thirteen  minutes, 
and  the  gas  collected  was  about  130  litres. 


THEORY    OF    RESPIRATION.  305 

The  cock  was  closed,  the  air  was  permitted  to  cool  iii 
the  flasks,  and  the  pressure  and  temperature  determined. 
Then  these  flasks  were  placed  in  connection  with  three 
others  exhausted,  but  separated  from  the  first  by  tubes 
arranged  for  absorbing  moisture  and  carbon  dioxide. 

The  gas  was  made  to  pass  through  the  tubes  slowly 
by  opening  progressively  the  cocks,  and  when  the  gas 
ceased  to  pass  through  the  tubes  the  pressure  in  the 
first  flask  was  again  measured,  the  difference  giving  the 
amount  of  air  which  escaped.  The  increase  in  weight 
of  the  tubes  containing  the  alkaline  solutions  represents 
the  amount  of  carbon  dioxide  in  this  air. 

The  experimenters  operated  on  37  men  and  26  women 
of  various  ages,  with  results  which  we  will  now  state. 

The  respiratory  phenomena  attain  their  maximum 
energy  at  about  thirty  years  of  age  ;  they  increase  up  to 
this  age,  then  decrease  until  death.  From  20  to  30 
years  the  quantity  of  carbon  dioxide  exhaled  is  18  to 
20  litres  per  hour. 

Respiration  is  more  active  in  men  than  in  women. 
The  production  of  carbon  dioxide  is  greater  during 
digestion  than  when  fasting  ;  the  relation  increases  from 
24  to  33,  and  even  more.  At  the  age  of  puberty  there 
is  a  great  increase  in  the  production  of  carbon  dioxide 
in  man.  This  increase  is  arrested  in  woman  at  the  age 
when  menstruation  sets  in,  and  returns  during  several 
years  after  the  critical  age.  It  likewise  increases  during 
gestation. 

Respiration  is  feebler  during  sleep,  and,  according  to 
Scharling,  the  quantity  of  carbon  dioxide  produced 
during  sLeep  is  one-fourth  less  than  when  awake. 


306  ANIMAL    CHEMISTRY. 

Exhaled  air  contains  aqueous  vapour ;  this  fact  was 
observed  by  the  ancients,  for,  on  breathing  upon  glass, 
or  other  polished  surface,  a  condensation  of  droplets  of 
water  was  observed.  This  water  was  considered  as 
exclusively  derived  from  that  introduced  into  the  body 
with  the  food.  Lavoisier  distinguished  water  of 
pulmonary  transpiration,  proceeding  from  the  lungs, 
from  the  water  of  respiration  formed  by  the  combination 
of  oxygen  with  hydrogen. 

According  to  Valentin,  the  weight  of  water  exhaled 
from  the  lungs  during  24  hours  is,  in  the  mean,  540 
grammes,  while,  according  to  Barral,  it  attains  to  nearly 
650  grammes. 

It  seems  certain  that  expired  air  removes  from  the 
body  a  small  amount  more  of  nitrogen  than  the  air  iii- 
haled  introduces.  According  to  Edwards,  animals  absorb 
nitrogen  from  the  air,  and  disengage  a  small  quantity 
of  the  nitrogen  of  their  own  substance.  The  researches 
of  Regnault  and  Eeiset,  however,  have  demonstrated 
that  the  nitrogen  of  the  air  is  not  ordinarily  absorbed 
during  respiration,  and,  consequently,  does  not  assist 
in  nutrition  under  normal  conditions. 

Among  other  principal  conclusions  of  their  important 
investigation  were  the  following  : — 

1st.  When  warm-blooded  animals  are  submitted  to 
their  habitual  alimentary  regimen,  they  always  dis- 
engage nitrogen ;  but  the  quantity  of  this  gas  is  very 
small ;  it  never  amounts  to  more  than  —£--„-  of  the  weight 
of  oxygen  consumed,  and  is  often  less  than  T7hi- 

2nd.  When  the  animals  are  in  a  state  of  inanition 
they  often  absorb  nitrogen,  and  tlip  proportion  varies 


THEORY    OF    RESPIRATION.  307 

between  the  same  limits  as  that  of  the  nitrogen  exhaled 
in  the  case  where  they  are  subjected  to  their  natural 
regimen.  The  absorption  of  nitrogen  almost  always 
occurs  in  starving  birds,  but  very  rarely  in  mammalia. 

3rd.  The  relation  between  the  quantity  of  oxygen 
contained  in  the  carbon  dioxide  and  the  total  quantity 
of  oxygen  consumed  seems  to  depend  much  more  upon 
the  nature  of  the  food  than  upon  the  class  to  which  the 
animal  belongs.  This  proportion  is  greater  when  the 
animals  are  fed  with  grain,  and  in  this  case  exceeds  the 
normal  or  unity.  When  they  are  fed  exclusively  with 
meat,  this  proportion  becomes  less,  and  varies  from 
0.62  to  0.80. 

With  a  diet  of  vegetables,  the  relation  is  in  general 
intermediate  between  the  two  just  given. 

4th.  The  relation  between  the  oxygen  contained  in 
the  carbon  dioxide  and  the  total  oxygen  consumed 
varies  for  the  same  animal  from  0.62  to  1.04,  according 
to  the  diet  to  which  it  is  subjected.  It  is  therefore  far 
from  being  constant. 

5th.  The  quantities  of  oxygen  consumed  by  the 
same  animal  in  equal  times  vary  much,  according  to 
the  different  periods  of  digestion,  the  amount  of  activity, 
and  many  other  circumstances.  With  animals  of  the 
same  species,  and  of  the  same  weight,  the  consumption 
of  oxygen  is  greater  in  young  than  in  adults ;  it  is 
greater  in  lean  healthy  animals  than  in  very  fat  ones. 

6th.  Warm-blooded  animals  disengage  by  respiration 
small  and  almost  indeterminable  quantities  of  ammonia 
and  sulphuretted  gases. 


3§8  ANIMAL    CHEMISTRY. 

7th.  The  respiration  of  animals  of  different  classes 
in  an  atmosphere  containing  two  or  three  times  as 
much  oxygen  as  normal  air  presents  no  difference  from 
that  which  takes  place  in  our  terrestrial  atmosphere. 
The  consumption  of  oxygen  is  the  same  ;  the  relation 
between  the  oxygen  contained  in  the  carbon  dioxide 
and  the  total  oxygen  consumed  undergoes  no  perceptible 
change  ;  the  proportion  of  nitrogen  gas  exhaled  is  the 
same,  and  the  animals  do  not  seem  to  perceive  that  they 
are  in  an  atmosphere  different  from  the  ordinary  one. 

In  the  recent  experiments  of  Bert,  he  observed  that 
if  an  animal  be  exposed  to  the  influence  of  pure  oxygen 
under  a  pressure  of  four  atmospheres,  it  gives  signs  of 
discomfort,  which  are  followed  by  violent  convulsions, 
and  death  ensues  if  the  pressure  be  increased  to  five 
atmospheres. 

It  is  to  the  action  of  the  oxygen  and  not  to  the 
increased  pressure  that  these  effects  are  to  be  attributed  ; 
for  if  a  swallow  be  exposed  to  air  under  a  pressure  of 
three  atmospheres,  and  then  nitrogen  at  twenty  atmo- 
spheres admitted,  the  animal  perishes,  slowly  asphyxi- 
ated, without  convulsions.  The  convulsions  also  ensue 
if  the  oxygen  under  four  atmospheres  pressure  be 
replaced  with  air  under  twenty  atmospheres.  The 
analysis  of  the  gases  of  the  blood  shows  that  when 
deatli  ensues  the  blood,  instead  of  containing  18  to 
20  c.c.  of  oxygen  in  100,  as  in  ordinary  conditions, 
contains  35  c.c.  An  unusual  combustion  does  not  take 
plane,  for  the  temperature  of  the  animal  seems  to  fall 
sensibly,  or  at  least  it  does  not  increase. 


SUMMARY   OF    THE    THEORY   OF    RESPIRATION.        309 

On  the  other  hand,  when  the  pressure  of  the  air 
is  diminished  until  death  ensues,  the  bird  perishes 
asphyxiated  in  the  midst  of  a  pure  air  hardly  con- 
taining any  carbon  dioxide.  Then  death  takes  place 
because  the  pressure  of  the  oxygen  is  not  sufficient  to 
maintain  in  the  blood  the  quantity  necessary  for  pro- 
ducing vital  phenomena. 

Thus  an  aeronaut  would  be  able  to  mount  without 
danger  to  much  greater  heights  than  have  hitherto 
been  reached  if  he  would  inhale  oxygen  when  suffering 
from  the  rarefaction  of  air. 

On  the  other  hand,  divers  would  be  able  to  work  at 
great  depths  without  danger  if,  instead  of  sending  them 
pure  air,  a  mixture  of  air  and  nitrogen  of  definite 
proportions  were  supplied. 


SUMMARY    OF    THE    THEORY    OF    RESPIRATION. 

Priestley  was  cognizant  of  the  fact  that  air  and 
oxygen — which  latter  element  he  had  just  discovered — 
had  the  property  of  reddening  venous  blood,  and  that 
carbon  dioxide  turned  arterial  blood  to  a  brown  colour. 
But,  misled  by  the  phlogistic  theory,  he  did  not  have 
the  satisfaction  of  establishing  the  theory  of  respiration 
and  combustion — an  honour  which  belongs  entirely  to 
Lavoisier. 

This  theory  enabled  the  latter  chemist  to  explain 
animal  heaj;,  and  in  1789  he  wrote  the  following : — 

"  Respiration  is  simply  a  slow  combustion  of  carbon 


310  ANIMAL   CHEMISTRY. 

and  hydrogen  which  is  similar,  on  the  whole,  to  that 
which  takes  place  in  the  flame  of  a  candle.  Animal 
organisms  are  thus  true  combustibles,  as  they  are 
oxidized  in  respiration  and  consumed  at  the  expense 
of  the  oxygen  of  the  air." 

As  to  the  part  of  the  body  in  which  the  combustion 
took  place,  he  did  not  claim  to  make  any  assertion. 

Lagrange  was  the  first  to  state  that  combustion 
takes  place  in  the  capillaries,  and  since  then  many 
investigators  have  established,  by  experiment,  the  truth 
of  this  assertion. 

In  order  to  show,  however,  that  the  change  in  the 
colour  of  the  blood  takes  place  in  the  lungs,  we  have 
only  to  observe  the  lungs  of  a  frog  after  having,  by 
appropriate  dissection,  exposed  them  to  view.  The 
transparency  of  the  membranes  admits  of  the  difference 
in  the  colour  of  the  blood  being  plainly  seen  before 
and  after  leaving  the  lungs. 

The  air  produces  this  change,  for  if,  as  was  done  by 
Bichat,  a  cock  be  adapted  to  the  carotid  artery  of  a 
dog,  the  blood,  which  is  red,  becomes  black  when  air  is 
prevented  from  entering  the  lungs  by  closing  a  cock 
placed  in  the  trachea ;  and  the  red  colour  returns  as 
soon  as  air  is  allowed  to  enter. 

The  fact,  perfectly  demonstrated  above,  in  regard  to 
the  relative  insufficiency  of  oxygen  and  the  abundance 
of  carbon  dioxide  in  the  venous  blood  as  compared  with 
arterial  blood,  proves  indirectly  that  an  absorption  of 
oxygen  and  a  production  of  carbon  dioxide  takes  place 
in  the  capillaries  situated  between  the  arteries  and 


THE    BLOOD    AND    ATMOSPHERIC    OXYGEN.  311 

veins.  But  Spallanzani,  and  especially  W.  Edwards, 
have  directly  proved  this  important  fact.  The  latter 
removed  the  gases  from  the  lungs  of  a  frog  by  com- 
pressing them  under  mercury,  and  introduced  the 
animal  under  a  bell-glass  filled  with  hydrogen  over 
mercury.  The  frog  breathed  for  quite  a  long  time ; 
the  analysis  of  the  gases  showed  that  they  contained  a 
volume  of  carbon  dioxide  much  greater  than  that 
exhaled  by  the  animal  under  ordinary  conditions. 

OXYGEN. — Oxygen  is  not  merely  dissolved  by  the 
blood.  If  such  were  the  case,  the  blood  of  persons 
living  in  mountains  would  contain  less  than  that  of 
those  who  live  in  the  lowlands.  Nothing  of  this  kind 
has  been  observed  at  Quito  (2,908  metres  above  the 
level  of  the  sea),  at  Potosi  (4,166  metres),  or  at  Deba 
(4,812  metres)  ;  in  the  latter  place,  the  atmospheric 
pressure  is  scarcely  half  of  that  at  the  level  of  the  sea, 
and  consequently  the  blood  should  contain  but  half  the 
amount  of  oxygen.  On  the  other  hand,  Regnault  and 
Reiset  have  observed  that  the  absorption  of  oxygen  does 
not  increase  when  animals  respire  an  atmosphere  con- 
taining two  or  three  times  as  much  oxygen  as  ordinary 
air. 

It  is  well  known  that  the  quantity  of  any  gas  dis- 
solved is  directly  proportional  to  the  pressure  which 
the  gas  sustains. 

On  the  other  hand,  the  coefficient  of  solubility  of 
oxygen  in  the  blood  at  15°  is  0.0287,  or  very  nearly 
that  of  oxygen  in  water ;  and  it  is  the  same  for  serum. 
Hence  it  results  that  one  litre  of  blood  should  dissolve 


312  ANIMAL    CHEMISTRY. 

only  °-^*-  of  oxygen,  pr  5.7  c.c.,  while  the  real  amount 
contained  in  the  blood  is  92  to  95  c.c.  (Fernet) . 

It  is  therefore  probable,  d  priori,  that  oxygen  forms 
a  combination  with  one  of  the  principles  of  the  blood. 
This  principle  is  not  the  serum ;  for  if  the  blood  be 
defibrinated  and  the  globules  removed,  the  serum 
dissolves  scarcely  more  oxygen  than  water.  If,  on  the 
contrary,  defibrinated  blood  containing  the  globules 
be  agitated  with  oxygen,  it  absorbs  much  more  oxygen 
than  the  serum  deprived  of  globules.  If  the  globules 
simply  dissolved  the  oxygen,  the  proportion  would 
increase  as  the  temperature  decreased  ;  but  this  is  not 
the  case.  At  40°  to  45°  a  maximum  absorption  is 
observed,  and  at  a  higher  temperature  the  phenomena 
of  oxidation  take  place.  A  combination  is  therefore 
produced,  and  it  follows  from  what  we  have  said  above 
that  the  haemoglobin  of  the  globules  must  be  the  agent 
which  effects  the  combination  with  the  oxygen.  This 
combination  is  also  extremely  unstable,  as  the  oxygen 
may  be  almost  completely  removed  in  a  vacuum. 

The  oxygen  of  the  blood  acquires  an  energetic 
oxidizing  power,  comparable  to  that  of  ozone,  at  a  tem- 
perature where  ordinary  oxygen  is  inactive.  In  fact, 
essence  of  turpentine,  to  which  a  few  globules  of  arterial 
blood  are  added,  turns  litmus  at  once  blue,  in  the  same 
manner  as  when  agitated  in  the  air  in  the  sunlight. 
Hydrogen  peroxide  dissolves  pyrogallic  acid  without 
becoming  coloured ;  but  if  to  this  solution  platinum 
black  or  blood  globules  be  added  the  brown  coloration 
is  at  once  produced. 


THE    BLOOD    AND    CARBON    DIOXIDE.  313 

The  blood  contains,  besides  oxygen  combined  with 
the  globules,  a  small  proportion  of  this  gas  dissolved 
in  the  serum. 

It  should  be  also  stated  in  this  connection  that  a 
small  portion  of  the  oxygen  inhaled  is  employed  to 
oxidize  the  sulphur  of  complex  sulphur  compounds, 
the  albuminoids,  etc. 

CARBON  DIOXIDE. — Carbon  dioxide  is  not,  like 
oxygen,  combined  with  the  globules.  Fernet  has 
determined  the  quantity  of  this  gas  which  the  con- 
stituents of  the  serum — water,  carbonate,  phosphate, 
and  chloride  of  sodium — are  capable  of  absorbing, 
either  by  dissolving  or  combining  with  it ;  and  the 
result  of  these  researches  shows  that  the  quantity  of 
carbon  dioxide  found  in  the  blood  is  very  nearly  equal 
to  that  which  the  serum  alone  absorbs. 

The  quantity  of  carbon  dioxide  exhaled  is  less  during 
sleep  than  when  awake,  for,  as  the  organs  are  at  rest, 
the  oxidation  is  not  then  so  great. 

The  carbon  dioxide  is  not  derived  from  the  atmo- 
sphere, since  the  gases  exhaled  contain  more  than  the 
air,  and  its  proportion,  which  is  small  in  arterial  blood, 
is  observed  to  increase  as  this  liquid  traverses  the 
organs  in  which  the  combustion  takes  place.  This  gas 
is  therefore  formed  in  the  body,  and  is  rejected  as  a 
waste  product. 

F.  M.  Eaoult  (9-82-1101)  finds,  as  a  result  of  recent 
experiments,  that  the  presence  of  carbon  dioxide  in 
inhaled  air  causes  a  diminution  of  the  carbon  dioxide 
exhaled,  and  therefore  in  the  oxygen  consumed. 


314  ANIMAL    CHEMISTRY. 

NITROGEN. — Nitrogen  forms  at  the  most  one-tenth 
of  the  gases  of  the  blood,  which  contains  2  to  3  per 
cent,  of  this  gas,  while  the  serum  dissolves  only  1  per 
cent. ;  consequently  there  is  for  this  gas  a  special  action 
not  as  yet  explained. 

To  review,  the  vesicles  of  the  lungs  act  as  a  porous 
membrane ;  and  this  organ  should  be  regarded  as  an 
apparatus  for  the  exchange  of  gaseous  bodies. 

The  blood  which  has  become  red  in  the  lungs 
retains  this  colour  until  it  enters  the  capillaries.  On 
leaving  the  capillaries  it  is  darker,  and  instead  of" 
oxygen  it  contains  carbon  dioxide.  Consequently  it  is 
in  this  transit  that  the  combustion  takes  place.  This 
combustion  either  occurs  in  the  capillaries  proper,  or  the 
oxygen  traverses  their  dialyzing  walls  and  penetrates 
into  the  depths  of  the  tissues  whence  the  carbon  dioxide 
escapes.  This  latter  hypothesis  is  more  in  favour  than 
the  first.  There  is  an  exchange  of  gases  in  the  centre 
of  these  structures  as  in  the  lungs,  and  the  oxygen 
coming  from  the  air  penetrates  into  the  innermost  parts 
of  the  body  of  animals,  and  there  effects  the  oxidation 
of  the  tissues  themselves. 


VARIATIONS    IN    THE    GASES    EXPIRED   IN    PATHOLOGICAL 
STATES. 

We  have  but  little  information  on  this  point. 
According  to  Hervier  and  Saint-Lager  "  the  proportion 
of  carbon  dioxide  decreases  in  all  diseases  in  which 


GASES   EXHALED    IN    PATHOLOGICAL   STATES.         315 

respiration  is  impeded,  as  in  pulmonary  phthisis,  pneu- 
monia, pleurisy,  pericarditis,  eruptive  fevers,  and  typhoid 
affections." 

In  diabetes,  chlorosis,  anaemia,  and  in  diseases  in 
which  there  is  no  febrile  movement,  the  variations  in 
the  proportion  of  carbon  dioxide  are  hardly  appre- 
ciable. In  inflammations  the  carbon  dioxide  increases 
in  a  remarkable  manner. 

Bayer,  and  afterwards  Doyere,  have  affirmed  that 
the  air  exhaled  by  cholera  patients  contains  more 
oxygen  and  less  carbon  dioxide  than  the  air  normally 
expired.  The  quantity  of  oxygen  absorbed  is  always 
greater  than  that  of  the  carbon  dioxide  exhaled. 


316  ANIMAL    CHEMISTRY. 


NUTRITION. 

ANIMALS   cannot   live   unless   able   to    respire    and 
obtain  nourishment,  i.e.,  to  ingest  matters  which    are 
digested,  absorbed,  transported  to  the  blood  and  sub- 
mitted, subsequently,    to  the  action  of  oxygen. 

The  food,  carried  by  the  blood  into  the  different 
organs,  undergoes  therein  two  different  changes.  One 
part  is  burned,  as  coal  in  the  furnace,  producing  heat  and 
physical  energy.  The  remainder  becomes  organized  to 
form  the  tissues,  since  an  animal,  considered  even  in  an 
adult  state,  and  at  a  period  at  which  its  weight  does 
not  vary,  constantly  fixes  matter  in  its  organism,  and 
therefore  also  loses  an  equivalent  amount. 


ANIMAL    HEAT MUSCULAR    POWER. 

These  two  subjects  are  intimately  connected  with  one 
another,  and  with  respiration. 

The  temperature  of  animals,  and  even  that  of  plants, 
is  not  uniformly  that  of  the  medium  in  which  these 
beings  live.  It  varies  also  with  the  species.  In  man  it  is 
very  nearly  '67  degrees,  in  whatever  climate  he  may  live* 


ANIMAL    HEAT — MUSCULAR    POWER.  317 

The  two  extremes  of  temperature  in  which  man  can 
exist  are  very  remote.  He  alone  is  capable  of  dwelling 
in  all  latitudes,  in  the  most  varied  climates,  and  at 
heights  so  great  that  the  pressure  is  only  one-half  of 
that  at  the  level  of  the  sea. 

Different  portions  of  the  body  have  not  the  same 
temperature.  The  exterior  parts,  from  the  cooling  effect 
of  the  surrounding  medium,  are  reduced  in  temperature 
4  to  5  degrees  below  that  of  the  interior.  The  muscles 
are  1.5  to  2  degrees  warmer  than  the  cellular  tissue. 

It  is  the  blood  which,  traversing  the  whole  body, 
tends  to  equalize  the  heat  disengaged  in  the  different 
organs.  The  liberation  of  gases  in  the  lungs  lowers 
their  temperature  slightly,  and  especially  that  of  the 
left  cavities  as  compared  with  the  right.  The  venous 
blood  in  the  extremities  is  slightly  less  warm  than 
the  arterial  blood,  but  this  is  due  to  the  external 
position  of  the  vessels. 

The  conditions  which  cause  the  activity  of  the 
respiration  to  vary,  that  is,  the  absorption  of  oxygen, 
produce  also  a  corresponding  variation  in  rnirnal  heat. 
The  temperature  of  the  body  of  an  infant  or  an  old 
man  is  less  than  that  of  an  adult,  and  we  have 
observed  that  the  respiratory  phenomena  diminish  in 
energy  at  the  two  extreme  points  of  life. 

If  an  important  reduction  in  temperature  is  pro- 
duced after  eating,  it  must  be  attributed  to  the  fact 
that  the  blood  rushes  to  the  muscles  of  the  digestive 
apparatus,  which  act  with  increased  energy  at  this 
time. 


318  ANIMAL    CHEMISTRY. 

Like  the  fuel  of  an  ordinary  engine,  a  part  heats 
the  animal  machine,  the  other  is  converted  into  mus- 
cular activity,  which  produces  either  external  work 
(walking,  movements  of  the  arms,  head,  etc.),  or  in- 
ternal work  (digestion,  assimilation,  etc.).  Thus  the 
observed  heat  is  equal  to  the  difference  between  the 
heat  produced  and  the  heat  which  is  transformed  into 
work.  Now,  since  we  know  the  mechanical  equivalent 
of  heat,  that  is,  the  quantity  of  work  which  a  certain 
amount  of  heat  will  accomplish,  the  heat  produced  can 
be  measured. 

If  the  muscle  contracts  without  producing  mechanical 
effect,  the  heat  developed  will  be  greater,  since  there  is 
only  heat  developed,  and  that  not  utilized  in  the  form 
of  work.  But  even  if  the  muscular  power  does  produce 
an  external  mechanical  effect,  there  is  still  in  addition 
a  production  of  heat  in  the  interior  of  the  body.  Ex- 
periment has  shown  that  when  a  muscle  contracts  the 
quantity  of  oxygen  consumed  is  greater  than  when  it 
is  in  repose :  thus  100  volumes  of  blood,  leaving  a 
muscle  which  is  in  action,  instead  of  furnishing  6 
volumes  of  oxygen,  furnish  only  2  volumes. 

All  chemico-physiologists  are  in  accord  in  admitting 
that  heat  and  motion  are  due  to  the  oxidation  of  the 
food.  The  amount  of  carbon  dioxide  exhaled  does  not 
indicate  the  amount  of  oxidation  which  has  taken 
place  in  the  body.  Every  movement,  every  chemical 
action,  every  passage  of  the  food  from  a  solid  to  a 
liquid  state  in  the  blood,  all  friction  of  the  liquids 
in  the  body,  are  actions  which  go  to  produce  an 


ANIMAL    HEAT — MUSCULAR   POWER.  319 

elevation  or  decrease  of  temperature.  Consequently 
there  are  incessant  gains  and  losses  of  heat,  and  we 
perceive,  on  the  whole,  only  the  resujtant  of  these 
different  actions  of  which  the  complexity  is  extreme. 

The  carbon  dioxide  is  not  the  only  product  of  oxida- 
tion ;  water  and  other  matters  (urea,  uric  acid,  etc.)  are 
formed,  which  escape  in  the  different  excretions.  And 
the  whole  of  the  oxygen  which  oxidizes  is  not  derived 
from  the  air ;  a  considerable  part  is  obtained  from  the 
oxygen  of  the  food  itself. 

There  is  a  difference  of  opinion  as  to  the  manner  in 
which  the  action  is  produced.  According  to  some,  it 
results  from  the  oxidation  of  the  aliments  as  they  are 
found  in  the  blood.  Others  do  not  admit  that  the 
process  takes  place  in  the  blood,  but  that  it  is  a  direct 
oxidation  of  the  muscles  by  the  oxygen  which  produces 
heat  and  motion. 

The  second  view  is  that  most  generally  admitted.; 
nevertheless,  the  recent  researches  of  Meyer  and  Frank- 
land  on  this  subject  appear  to  prove  the  contrary. 

An  average  man  has  about  7.0  kilos  of  muscles, 
considered  in  a  dry  state.  According  to  Meyer,  they 
would  be  completely  oxidized  in  eighty  days  if  they 
served  to  produce  mechanical  work. 

It  is  rational  to  regard  the  muscles  as  instruments 
for  the  transformation  of  potential  energy  into  motion. 
We  can  only  give  a  few  conclusions  deduced  from  the 
work  of  Frankland. 

1st.  The  muscle  is  a  machine  destined  to  convert 
potential  energy  into  mechanical  force. 


320  ANIMAL    CHEMISTRY. 

2nd.  The  mechanical  force  of  the  muscles  is  derived 
principally,  if  not  wholly,  from  the  oxidation  of  the 
substances  contained  in  the  blood,  and  not  from  the 
oxidation  of  the  muscles  themselves. 

3rd.  In  man  the  principal  substances  employed  in 
the  production  of  muscular  power  are  non-nitrogenous ; 
but  nitrogenous  substances  may  also  be  employed  for 
the  same  object,  hence  the  great  increase  in  the  evolu- 
tion of  nitrogen  under  a  diet  of  animal  food,  even  with 
no  increase  in  the  amount  of  muscular  work  performed. 

4th.  Like  all  other  parts  of  the  body,  the  muscles  are 
constantly  being  renewed ;  but  this  renewal  is  not 
apparently  more  rapid  during  great  muscular  activity 
than  during  comparative  repose, 

5th.  After  a  sufficient  quantity  of  albuminous  sub- 
stances has  been  digested  for  the  renewal  of  the  tissues, 
the  best  food  for  the  production  of  work,  both  internal 
and  external,  are  the  non-nitrogenous  substances,  such 
as  oil,  fat,  sugar,  starch,  gum,  etc. 

6th.  The  non-nitrogenous  portions  of  the  food  which 
enter  into  the  blood  transform  all  their  potential  energy 
into  effective  force  ;  the  nitrogenous  substances,  on  the 
contrary,  leave  the  body,  taking  with  them  a  part  (one- 
seventh)  of  their  potential  force. 

7th.  The  transformation  of  dynamical  force  into 
muscular  power  is  necessarily  accompanied  by  a  pro- 
duction of  heat  within  the  body,  even  when  the 
muscular  force  is  exerted  exteriorly.  This  is,  without 
doubt,  the  principal  though  not  the  only  source  of 
animal  heat. 


TRANSFORMATION    OF    ALBUMINOID    SUBSTANCES.     321 

Fick  and  Wislicenus,  in  an  ascension  of  the  Faulhorn 
in  18b'5,  determined  the  amount  of  work  performed  by 
their  muscles,  and  the  quantity  of  muscular  matter 
oxidized  to  produce  this  work.  This  latter  calculation 
was  made  by  determining  the  amount  of  nitrogenous 
matters  in  the  urine  emitted,  and  collecting  them  in  the 
form  of  urea,  and  based  upon  the  fact  established  by 
Frankland,  that  1  gr.  of  dried  muscle  transformed  into 
urea  produces  4,368  heat  units.  They  arrived  at  the 
result  that  the  work  accomplished  was  about  twice  as 
great  as  that  which  would  be  produced  by  the  com- 
bustion of  the  substance  of  the  muscles  transformed 
into  urea. 


TRANSFORMATION    OF    FOOD    JN    THE 

We  recognize  three  principal  classes  of  food,  albumi- 
noid, farinaceous,  and  fatty. 

Transformation  of  Albuminoid  Substances.  —  It  was 
formerly  believed  that  albuminoid  matters  were  not 
modified  in  the  body,  but  simply  fixed  in  the  tissues, 
and  taking  no  part  in  the  respiratory  phenomena.  The 
name  of  plastic  food  given  to  these  bodies  illustrates 
perfectly  this  manner  of  regarding  them.  On  the  other 
hand,  the  fatty  and  farinaceous  bodies  were  thought  to 
take  part  in  the  production  of  the  respiratory  pheno- 
mena alone.  Hence  the  name  respiratory  aliments,  which 
has  been  given  them.  This  view,  however,  is  too  limited  ; 
carbon  dioxide  and  water  are  the  principal  but  not  the 
only  products  exhaled.  Others  are  formed,  as  urea, 
uric  acid,  and  these  substances  are  nitrogenous.  There 


322  ANIMAL    CHEMISTRY. 

escapes  also  in  the  gas  exhaled  by  the  lungs  a  certain 
quantity  of  free  nitrogen.  It  is  well  known  that  the 
framework  of  animal  tissues  is  nitrogenous  ;  but  it  is 
none  the  less  certain  that  different  tissues  are  filled 
with  non-nitrogenous  matters,  suoh  as  the  fat  of  adipose 
tissue  and  glycogenous  substances. 

The  albuminoid  matters  undergo  in  the  blood,  and 
afterwards  in  the  organs  to  which  the  blood  carries 
them,  numerous  transformations,  most  frequently  pro- 
duced by  oxidation.  To  prove  this  it  will  only  be 
sufficient  to  enumerate  the  different  nitrogenous 
principles  found  in  the  body.  These  are  mainly  : — 

Urea        .         .  .  CH4N20 

Uric  acid          .  .  C5H4N403 

Urine  <  Hippuric  acid  .  .  C,,H9N403 

i  Cystin      .         .  .  C3H7N802 

(  Xanthin .         .  .  C5H4N4O2 

Perspiration —  Sudoric  acid     .  .  C10H8016N  ? 

( Taurocholic  acid  .  C26H45N07S 

Liver  .     .     .  \  Q-lycocholic  acid  .  t  Co6!I43N06 

tCholesterin       .  .'  G)(;H44 


/  Leucin     .  .  .  CGH13NO2 

Pancreas       J  Tyrosin   .  .  .  C9HnN03 

[  Lactic  acid  .  .  C.jH603 

(Creatin'.  .  .  C4H9NS02 

Creatinin  .  .  C4H7N30 

,,     ,              I  Inosite     .  .  .  C6Ha  ,0t;  +  2H,0 

Muscles        .  •-   _      .       .,  rsTTXTri  g 

Inosic  acid  .  .  Lr)HsiN2U(;r 

Sarcosin  .  .  .  C3H7N02 

VSarcin  (Hypozanthin)  C5H4N40 
Osseous  tissue — Ossein. 


GLUCOSE  IN  THE  LIVER.  323 

TRANSFORMATION  OF  AMYLACEOUS  OR  FARINACEOUS 
FOOD. — Starchy  matters  are  only  found  in  small 
quantities  in  the  tissues  of  the  body — a  fact  which  is 
quite  natural  as  regards  carnivorous  animals,  but  very 
surprising  in  the  case  of  herbivorous  animals;  and 
which  seems  to  prove  that  starch  is  the  chief  respiratory 
aliment,  and  that  it  is  very  easily  oxidized  or  burned. 
The  greater  part  of  the  starch  is  transformed  into 
carbon  dioxide  and  water.  Another  portion  is  con- 
verted into  fat,  and  the  rest  (a  minute  fraction)  is  fixed 
in  certain  tissues. 

GLUCOSE  IN  THE  LIVER. — The  existence  of  amyla- 
ceous matter  in  animal  tissue  is  connected  with  a 
remarkable  discovery  made  in  1849  by  the  illustrious 
physiologist,  Claude  Bernard — a  discovery  which  we 
shall  now  describe,  as  well  as  the  researches  which  led 
to  it. 

If  a  carnivorous  animal  be  subjected  to  prolonged 
fasting,  sugar  will  be  found  in  the  hepatic  tissue.  The 
proportion  of  sugar  found  in  the  liver  of  carnivorous 
animals,  or  of  animals  fed  exclusively  with  meat,  is 
substantially  the  same  as  that  i»  the  liver  of  herbivorous 
animals,  or  of  animals  fed  with  amylaceous  or  saccha- 
rine food.  Hence  the  production  of  sugar  does  not 
depend  upon  the  existence  of  amylaceous  and  saccha- 
rine substances  in  the  food. 

Objections  might  be  raised  to  such  experiments,  on 
the  grounds  that  the  blood,  in  passing  through  the  liver, 
might  leave  sugar  behind  it  in  this  organ,  and  that 
sugar  is  merely  retained  and  accumulated  by  the  liver. 


ANIMAL    CHEMISTRY. 

Bernard  responds  to  these  suppositions  by  an  experi- 
ment as  interesting  as  it  is  conclusive.  If  a  dog  is  killed 
and  the  liver  removed,  and,  after  washing  this  organ 
in  such  a  manner  as  that  all  the  sugar  shall  be  dissolved, 
it  is  allowed  to  remain  exposed  to  the  air  for  a  day, 
it  is  found  to  again  contain  a  very  large  proportion  of 
sugar. 

If,  also,  the  blood  of  the  vena  porta  be  analyzed 
before  it  reaches  the  liver,  as  well  as  after  leaving  this 
organ  in  the  superior  hepatic  veins,  a  considerable 
increase  in  the  amount  of  sugar  is  observed.  In  order 
to  extract  the  sugar  of  the  liver,  the  latter  is  cut  into 
very  small  pieces  and  treated  with  boiling  or  even  with 
cold  water  till  nothing  more  is  dissolved.  The  liquid 
is  decoloured  with  animal  charcoal,  and  evaporated 
over  a  water  bath  almost  to  dryness,  and  the  residue 
treated  with  alcohol.  The  alcoholic  solution  furnishes 
glucose  on  evaporation. 

Bernard  found  23/27  gr.  of  sugar  in  the  liver,  weigh- 
ing 1,300  grammes,  of  a  hanged  criminal  of  forty-three 
years,  and  25.70  grammes  in  that  of  another,  aged 
twenty-two,  and  whose  liver  weighed  1,200  grammes. 

Glycogene. — Sugar  is  produced  in  the  hepatic  tissues 
by  means  of  a  third  substance — a  sort  of  animal  starch, 
designated  glycogcne — which  has  also  been  found  on 
the  internal  surface  of  the  amniotic  membrane  of 
ruminants,  between  the  maternal  and  foatal  placenta  of 
rodents,  in  the  muscles,  and  in  the  lungs  of  the  foetus, 
and  later  in  the  liver  ;  also  in  different  parts  of  the 
Crustacea  and  articulates. 


"GLUCOSE  IN  THE  LIVER.  325 

To  prepare  glycogene,  the  liver  of  a  dog  recently 
killed  is  cut  into  very  small  pieces  and  thrown  into 
boiling  water  to  precipitate  and  destroy  the  ferment 
which  would  otherwise  change  the  starch  into  sugar. 
The  fragments  are  now  withdrawn,  triturated  with 
animal  charcoal,  and  the  pulp  obtained  boiled  for  about 
twelve  minutes  with  five  times  its  weight  of  water, 
filtered,  and  the  residue  treated  with  additional  water. 
A  liquid  is  obtained,  from  which  the  glycogene  may  be 
precipitated  by  alcohol. 

Glycogene  is  a  white  powder,  soluble  in  water, 
which  it  renders  milky,  and  insoluble  in  alcohol.  The 
solution  turns  the  plane  of  polarization  strongly  to 
the  right.  It  has  the  composition  of  starch,  x  (C6H1005), 
is  coloured  violet-red  by  iodine,  is  converted  into 
pyroxam  by  fuming  nitric  acid,  and  furnishes  dextrine 
and  glucose  under  the  same  circumstances  as  vegetable 
starch. 

The  transformation  of  glycogene  into  sugar  is  effected 
by  means  of  a  ferment  .analogous  to  diastase,  which  is 
found  in  fresh  liver  and  even  in  the  blood. 

According  to  Pavy,  the  proportion  of  glycogene  in 
the  liver  varies  with  the  nutrition  ;  it  is  large  if  the 
food  is  vegetable,  and  is,  on  the  contrary,  small  if  the 

food  is  animal. 

Amount  of  Glycogene 

in  the  Liver. 

Dog  fed  with  amylaceous  food.     17.23  per  cent. 
„      „       „    meat.  .       6.97         „ 

„      „       „        „     mixed  with 

sugar       ....     14.50         „ 


326  ANIMAL    CHEMISTRY.  * 

Rouget  arrived  at  analogous  results.  On  the  other 
hand,  Sansou  has  announced  that  on  giving  animals 
very  farinaceous  food,  dextrin  is  found  in  the  blood 
and  even  in  the  muscles ;  consequently  muscles  sup- 
plied as  food  would  furnish  amylaceous  matters  directly. 
There  also  exists  in  the  muscles  a  saccharine  substance 
called  inosite,  C6H1206,  and  lactic  acid  ;  consequently  a 
diet  of  meat  forms  in  the  body  amylaceous  products. 

Amylaceous  matter  is  also  found  in  the  muscles  of 
new-born  mammalia,  and  in  the  muscles  of  an  organ 
when  in  absolute  repose  for  a  certain  time.  This  all 
leads  to  the  belief  that  there  is  an  amylaceous  matter 
which  takes  part  in  the  formation  of  muscular  tissues, 
but  which  disappears  under  ordinary  circumstances,  and 
is  transformed  into  inosite  and  lactic  acid. 

From  these  facts,  and  the  existence  of  glycogeue  in 
other  parts  of  the  body  than  the  liver,  it  follows  that 
the  liver  is  not  absolutely  the  only  organ  having  the 
property  of  transforming  starch  into  sugar,  but  that  it 
possesses  it  in  a  much  greater  degree  than  do  the 
others. 

The  sugar  thus  formed  in  the  liver  then  passes  into 
the  blood,  and  there  disappears,  under  normal  condi- 
tions, being  burned  by  the  oxygen  ;  but  certain  natural 
or  artificial  conditions  may  diminish  or  increase  the 
formation  of  this  sugar. 

If  the  spinal  cord  be  dissevered  below  the  phrenie 
nerves,  the  circulation  becomes  weaker  in  the  abdominal 
region,  the  temperature  is  lowered,  and  sugar  is  no 
longer  found  in  the  hepatic  veins. 


GLUCOSE    IN    THE    URINE.  327 

ARTIFICIAL   AND    NATURAL    DIABETES. 

It  is  observed  that  the  amount  of  sugar  increases  in 
the  blood  of  the  superior  hepatic  veins  when  the 
pneumo-gastric  nerves  are  irritated,  when  a  special 
point  in  the  wall  of  the  fourth  ventricle  is  pricked, 
when  essence  of  turpentine,  ether,  or  chloroform  is  in- 
jected into  the  vena  porta,  or  simply  when  large 
proportions  of  these  agents  are  inhaled,  or,  finally, 
when  poisoning'  is  produced  by  curarina,  strychnia, 
or  brucia. 

Let  us  follow  step  by  step  the  research  of  Bouchardat, 
in  order  to  study  the  theory  of  natural  diabetes.  And 
first  we  will  recall  the  fact,  that  the  digestion  of 
amylaceous  substances  takes  place  in  the  intestines 
under  the  action  of  the  pancreatic  and  intestinal  juices, 
that  the  greater  part  of  the  starch  is  only  changed 
into  dextrine  in  the  intestine,  and  that  the  further 
transformation  of  this  dextrine  takes  place  chiefly  in 
the  blood,  under  the  action  of  the  intestinal  diastase 
absorbed  simultaneously  with  the  dextrine. 

Whenever  there  is  an  excess  of  glucose  in  the  blood, 
this  sugar  passes  into  the  urine.  This  fact  may  be 
demonstrated  by  injecting  glucose  into  the  veins  :  if 
there  is  but  little,  none  is  found  in  the  urine  ;  if  there 
is  a  large  amount  present,  reagents  will  indicate  its 
presence  in  the  urinary  secretion. 

The  causes  which  produce  an  excess  of  glucose  in  the 
blood  may  be  of  two  opposite  characters  :  either  the 
sugar  is  due  to  too  great  a  secretion,  or  it  may  result 


328  ANIMAL    CHEMISTRY. 

from  an  insufficient  destruction ;  but  more  often  veri- 
table glycosuria  characterized  by  a  constant  excess  of 
sugar,  is  due  to'  both  of  these  causes  combined.  It  has 
been  demonstrated  that  the  sugar  passes  into  the  urine 
whenever  there  is  more  than  3  to  5  grammes  in  the 
blood  at'  one  time. 

There  may  be  an  incompleteness  in  the  destruction 
of  the  glucose  in  the  blood,  either  because  the  oxygen 
is  not  present  in  sufficient  quantity  or  because  it  meets 
with  substances  which  are  more  easily  oxidized. 

Diabetes  will  result  when,  the  nutrition  being  very 
starchy,  there  is  an  excessive  transformation  of  amyla- 
ceous substance  into  glucose  in  the  digestive  canal.  In 
fact  the  glucose  is  observed  to  increase  with  the  propor- 
tion of  amylaceous  food.  In  persons  afi'pfted  with 
glycosuria  the  transformation  takes  place  in  the  stomach, 
and  this  fact  consequently  explains  why  all  albuminoid 
substances  are  susceptible  of  acting  upon  starch ;  they 
differ  only  in  the  rapidity  of  their  action.  It  has  also 
been  shown  that  if  the  pancreas  of  a  pigeon  be  removed 
it  will  still  be  able  to  digest  amylaceous  substances. 
Bouchardat  has  also  observed  that  the  stomach  of 
persons  having  glycosuria  is  generally  very  much  en- 
larged, and  that  persons  who  have  a  tendency  to 
diabetes  prefer  farinaceous  food,  that  they  eat  a  great 
deal,  and  also  that  they  eat  rapidly,  which  circum- 
stances occasion  a  longer  sojourn  of  the  food  in  the 
stomach.  When  an  organ  is  much  used  it  acquires 
greater  strength,  and  it  is  not  unreasonable  to  admit 
that  under  these  circumstances  the  gastric  juice  may 


TRANSFORMATION    OF    FATTY    SUBSTANCES.  329 

not  be  sensibly  changed,  and  become  incapable  finally 
of  dissolving  amylaceous  matter. 

Diabetes  is  accompanied  by  continual  thirst ;  hence 
it  will  be  understood  that  since  the  food  requires 
8  to  10  times  its  weight  of  water  for  digestion,  the 
gastric  juice  must  be  insufficient  if  the  digestion  of  the 
farinaceous  food  takes  place  in  the  stomach  at  the  same 
time  as  the  albuminoid. 

The  sugar  in  the  urine  of  diabetic  persons  ordinarily 
disappears  on  submitting  them  to  a  diet  formed  ex- 
clusively of  meat,  if  the  disease  is  not  too  advanced. 

In  general,  any  cause  on  the  other  hand  which  pro- 
duces a  diminution  of  the  respiratory  phenomena  tends 
to  retard  the  destruction  of  glucose  in  the  blood  and 
produce  diabetes  if  the  tissues  are  saturated  with 
glycogenic  matters. 

TRANSFORMATION    OF    FATTY    SUBSTANCES. 

It  has  been  established  by  a  large  number  of  experi- 
menters, who  have  operated  upon  different  animals,  that 
all  of  them  not  only  assimilate  fatty  matters,  but  that 
they  produce  fat  as  well.  Fat  alone  given  as  food  pro- 
duces inanition.  If  animals  be  submitted  to  varied 
nutrition,  there  is  much  more  assimilated  fat  found 
than  there  was  in  the  food  originally  supplied  them. 
Fatty  bodies  mixed  with  the  other  food  facilitate 
growth.  Amylaceous  and  saccharine  substances  are 
readily  changed  by  digestion  into  fatty  matters.  It 
has  not  been  demonstrated  that  nitrogenous  foods  are 
transformed  into  fats. 


330  ANIMAL    CHEMISTRY. 

The  R6le  of  Mineral  Compounds  in  Nutrition  is  but 
little  understood.  Iron  exists  in  different  parts  of  the 
body,  and  principally  in  the  blood  globules. 

Sodium  chloride  is  found  in  most  animal  fluids.  It  is 
thought,  as  we  have  already  stated,  that  this  substance 
IP  the  origin  of  the  hydrochloric  acid  of  the  gastric  juice, 
and  of  the  soda,  which  is  found  in  the  intestinal  juices. 
It  is  known  that  this  salt  forms  a  compound  with  glucose 
(p.  186),  also  the  existence  of  a  compound  of  sodium 
chloride  and  urea  has  been  shown  ;  and  this  is  the  reason 
for  the  belief  that  salt  assists  in  the  transformation  and 
elimination  of  sugar  and  of  urea.  It  aids  in  the  solution 
of  albumen  and  casein  in  certain  humours.  It  prevents 
the  dissolution  of  the  blood  globules,  of  the  chyle  and 
lymph,  and  we  have  reason  to  believe  that  it,  like  other 
salts  elsewhere,  is  an  important  factor  in  the  absorption 
of  liquids  by  different  membranes. 

Weiske  and  Wildt  (7-1874-123)  have  made  inves- 
tigations as  to  the  action  of  food  poor  in  lime  and 
phosphoric  acid,  upon  animals  of  rapid  growth.  They 
experimented  upon  three  lambs  about  two  and  a-half 
months  old,  and  in  a  healthy  condition,  feeding  one 
with  food  poor  in  lime  compounds,  one  with  food  poor 
in  phosphoric  acid,  and  the  third  with  the  usual  kind  of 
food;  while  the  latter  prospered  and  gained  13.5 
pounds  in  fifty-five  days,  the  first  two  lost  thirteen  and 
fourteen  pounds  in  weight,  and  were  by  this  time 
nearly  dead.  The  animals  having  been  killed,  the  com- 
position of  their  bones,  as  regards  their  inorganic  con- 
stituents, were  alike,  but  the  amount  of  fat  in  the  bones 


TRANSFORMATION    OF    FATTY    SUBSTANCES.  331 

of  the  animal  fed  with  normal  food  was  greater  than  in 
both  the  others.  A  diet  poor  in  calcium  and  phospho- 
rous compounds  does  not  affect  the  constitution  of  the 
bones  as  regards  their  mineral  constituents. 

Sodium  Phosphate  is  capable  of  facilitating  the  absorp- 
tion of  carbon  dioxide  by  the  blood,  and  consequently 
it  is  regarded  as  playing  an  important  part  in  re- 
spiration. 

Calcium  Phosphate  is  found  in  the  majority  of  animal 
substances.  This  salt  forms  the  greater  part  of  the 
mineral  matter  of  the  bones,  it  exists  in  the  ash  of 
albuminoid  compounds.  It  enters  the  body  dissolved 
in  water  by  means  of  carbonic  acid. 

This  substance,  as  well  as.  the  calcium  carbonate, 
magnesium  phosphate,  and  silica  assist  in  giving  solidity 
to  the  animal  structure,  and  Chossat  has  asserted  that 
the  bones  of  pigeons  completely  deprived  of  calcium 
phosphate  become  so  thin  as  to  break.  Magnesium 
phosphate  cannot  replace  calcium  phosphate. 

Weiske  (36-'77)  has  investigated  the  influence  of 
common  salt  upon  the  live-weight  and  the  disassociation 
of  nitrogen  in  various  animals,  and  ascertained  :  that  if 
the  amount  of  salt  in  the  food  increases,  and  the  animal 
be  allowed  all  the  water  it  desires,  the  amount  of  water 
consumed  increases ;  that  with  the  increase  of  salt  in 
the  food  and  the  consumption  of  water,  as  far  as  an 
increase  in  the  production  of  urine  accompanies  the 
same,  the  disassociation  of  nitrogen  increases :  that 
when  the  salt  is  removed,  the  consumption  of  water, 
as  well  as  the  production  of  urine,  and  disassociation  of 


332  ANIMAL    CHEMISTRY. 

nitrogen,  decreases ;  nevertheless  the  latter  remains 
higher  for  a  longer  time  than  if  a  large  ingestion  of  salt 
had  not  taken  place.  The  increase  in  weight  following 
a  diet  composed  largely  of  salt  is  not  due  to  increase  in 
the  amount  of  flesh,  but  to  the  accumulation  of  water 
in  the  body.  Salt  given  in  the  food  increases  the  desire 
for  eating,  but  a  notable  increase  or  decrease  in  the 
digestibility  of  the  food  has  not  been  proven. 


UB1.NK.  333 


URINE. 

HUMAN  urine  in  its  normal  state  is  a  liquid  of  an 
amber  colour,  the  concentration  of  which,  and  conse- 
quently the  density,  varies  with  the  age,  sex,  and  state 
of  digestion.  This  secretion  is  much  more  abundant, 
relatively,  in  infants  than  in  grown  persons,  but  the 
urine  of  infants  is  also  richer  in  water,  paler  and  less 
dense  than  that  of  adults.  Parrot  and  A.  Robin  have 
lately  (9-82-104)  studied  the  urine  of  newly-born 
infants,  and  find  that  the  secretion  amounts  to  four 
times  as  much,  referred  to  the  weight  of  the  body,  a& 
in  adults. 

The  quantity  of  urine  in  woman  is  to  that  in  man 
nearly  in  the  proportion  of  13  to  12. 

The  urine  of  man  is  pale,  and  charged  with  water 
after  abundant  ingestions  of  this  liquid.  Normal 
urine  is  that  obtained  soon  after  rising,  its  density  is 
about  1.018,  it  varies  between  1.012  and  1.022;  its 
density  may  fall  as  low  as  1.003,  and  rise  to  1.030 
after  a  hearty  repast ;  it  is  then  yellow. 

Water  is  evacuated  from  five  to  six  hours  after 
having  been  taken  into  the  system.  The  proportion  of 
urine  is  extremely  variable ;  1 ,200  to  1,300  grammes 

H 


334  ANIMAL    CHEMISTRY. 

is  about  the  mean  in  men  in  twenty-four  hours ;  1,300 
to  1,400  grammes  in  women.  But  this  quantity  may 
sometimes  increase  to  2,000  grammes,  and  descend  to 
900  grammes. 

The  three  principal  causes  which  influence  the 
amount  of  this  secretion  are  : — 

1st.  The  nature  of  the  blood  ;  a  very  aqueous  blood 
increases  it. 

2nd.  The  rapidity  of  circulation  in  the  kidneys. 

3rd.  The  activity  of  the  pulmonary  and  cutaneous 
respiration.  The  urinary  secretion  varies  in  inverse 
proportion  to  the  respiratory  phenomena ;  thus  the 
quantity  of  urine  emitted  is  greater  in  winter  than  in 
summer,  in  cold  countries  than  in  warm  countries. 
After  a  cold  bath  the  urinary  secretion  attains  its 
maximum. 

Certain  salts — nitre,  for  example — increases  the 
quantity  of  urine ;  they  are  denominated  diuretics. 

Other  substances  retard  and  diminish  this  secretion, 
as  cantharides,  etc. 

The  proportion  of  solids  extracted  from  the  body  by 
the  urine  may  vary  from  40  to  80  grammes  in  twenty- 
four  hours. 

Composition  of  Normal  Urine  of  Man. 

Water.         .         .  936.76        931.42        932.41 
Solid  constituents.     63.24          68.58          67.59 


1000.00      1000.00      1000.00 


INFLUENCE    OF    FOOD    ON    THE    URINE. 


335 


The  solids  are  composed  of — 


Urea   . 

Uric  acid 

Lactic  acid  . 

Aqueous  extract   . 

Alcoholic  extract . 

Lactate  of  ammo- 
nium 

Chloride  of  sodium 
and  of  ammo- 
nium 

Alkaline  sulphates 

Sodium  phosphate 

Calcium  and  mag- 
nesium phos- 
phates 

Mucus .         .         • 


31.45 
1.02 
1.49 
1.62 

10.06 

1.89 


3.64 
7.31 
3.76 


32.91 
1.07 
1.55 

0.59 
9.81 

1.96 


3.60 

7.29 
3.66 


1.18 
0.10 


32.90 
1.07 
1.51 

0.63 
10.87 

1.73 


3.71 
7.32 
3.98 


1.10 
0.11 


63.48 


63.72          64.90 
(Lehman.) 


INFLUENCE    OF    THE    FOOD    ON    THE    COMPOSITION    OF 
THE    URINE. 


Nature  of  the  Food. 

Solids  in 
1000  parts. 

Urea. 

Uric  Acid. 

Lactic 
Acid  and 
Lactates. 

Extractive 
Matters. 

Honev          .... 

67  82 

32  498 

1.183 

2.725 

10  489 

Animal    

87.44 

53.198 

1.478 

2.167 

15.196 

Vegetable     .... 
Non-nitrogenous  .     . 

59.24 
41.68 

22.481 
i    14.408 

i 

1.021 
0.735 

2.669 
5.276 

6.499 
11.854 

(Lehman.) 


336  ANIMAL    CHEMISTRY. 

Normal  human  urine  is  acid.  This  acidity  is  due 
to  the  action  of  the  uric  acid  and  other  acids  of  the 
urine  upon  the  alkaline  phosphates.  These  acids 
deprive  them  of  a  portion  of  their  alkali,  and  acid 
phosphates  result.  Uric  or  hippuric  acid  may  also 
be  found  in  excess  in  urine. 

The  quantity  of  free  acid  evacuated  in  twenty-four 
hours  represents  2.  to  2.5  grammes  of  oxalic  acid. 

The  reaction  of  the  urine  depends  upon  the  character 
of  the  food.  In  fact,  this  secretion  is  alkaline  in  herbi- 
vorous animals,  since  their  food,  which  is  very  rich  in 
carbon,  forms  bicarbonates  with  the  bases  which  are  in 
this  secretion ;  but  the  urine  of  an  herbivorous  animal 
may  be  rendered  acid  on  submitting  it  to  a  diet  of  flesh 
food.  The  urine  of  herbivorous  animals  is  turbid,  and 
contains  urea,  hippuric  acid,  and  a  small  quantity  of 
phosphates  ;  it  does  not  contain  uric  acid. 

Inversely  the  urine  of  carnivorous  animals  is  acid 
and  clear.  It  is  rendered  alkaline  by  forcing  the 
animals  to  an  exclusive  vegetable  diet. 

The  urine  of  carnivora  contains  more  urea  and  uric 
acid  than  that  of  man  or  herbivorous  animals,  while 
hippuric  acid  is  wanting  in  it.  Regaiding  the  occur- 
rence of  phenol,  E.  Bauman  has  recently  observed  that 
albumen  and  pancreas  in  putrefying  form  a  certain 
quantity  of  phenol,  and  he  believes  in  this  reaction  can 
be  found  an  explanation  of  the  existence  of  phenylsul- 
phates  in  the  urine  of  dogs  fed  exclusively  with  meat 
(60-77-685). 

Violent  exercise,  fatigue,  and  excesses  render  human 


AMMONIACAL    URINE.  337 

urine  alkaline.  This  fact  is  due  to  the  combustion 
which,  under  these  circumstances,  transforms  the  uric 
acid  into  urea,  and  this  body  does  not  possess,  like  uric 
acid,  the  property  of  removing  from  the  phosphates  a 
portion  of  the  alkali  which  they  contain. 

Gosselin  and  A.  Eobin  (9-78-72)  hare  made  experi- 
ments upon  animals,  injecting  ammoniacal  urine  sub- 
cutaneously,  and  found  that  animals  subjected  to  this 
treatment  became  feverish,  and  when  larger  quantities 
were  injected  they  died.  Thus  in  diseases  of  the 
bladder,  the  ammoniacal  urine,  if  reabsorbed,  must  be 
deleterious,  hence  it  would  be  advantageous  to  the 
patient  that  the  amount  of  ammonium  carbonate  in  the 
urine  be  reduced ;  this,  according  to  investigations  of 
Gosselin  and  Eobin,  is  effected  by  the  administration 
of  benzoic  acid.  Pasteur  (9-78-46)  claims  that  the 
ammoniacal  nature  of  urine  is  due  to  the  action  of  a 
ferment  which  obtains  entrance  through  the  urinary 
passages,  or  sometimes  is  introduced  mechanically  by 
means  of  chirurgical  instruments.  He  recommends, 
therefore,  that  the  instruments  before  being  used  be 
plunged  into  boiling  water,  or  heated,  then  quickly 
cooled,  and  at  once  employed. 

A.  Lailler  (9-78-361)  is  of  the  opinion  that  the 
ammoniacal  fermentation  of  urine  depends  in  a  great 
measure  on  the  amount  of  mucus  it  contains. 

Grubler  (9-78-1054)  asserts  that  the  decomposition  of 
urea  into  ammonium  carbonate,  as  is  the  case  in  the 
bladder  in  certain  diseases  of  this  organ,  is  due  to  small 
pus-corpuscles  (neocytes). 


338  ANIMAL    CHEMISTRY. 

W.  Zueker  (60-1875-1670)  has  lately  found  that 
after  a  diet  composed  wholly  of  meat,  the  urine  of  a  dog 
contained  for  every  100  parts  by  weight  of  nitrogen,  12 
to  14  of  phosphoric  acid  ;  when  fed  with  potatoes  and 
bread,  it  contained  20  to  30  of  phosphoric  acid  to  100 
of  nitrogen.  In  a  healthy  man,  20  to  25  years  of  age, 
the  food  being  mixed  and  sufficient,  the  urine  contains 
17  to  19  of  phosphoric  acid  to  100  of  nitrogen ;  with  a 
diet  of  meat  the  proportion  of  phosphoric  acid  decreases, 
with  a  vegetable  diet  it  increases.  The  time  of  day 
apd  the  state  of  health  have  great  influence  upon  the 
relative  proportion  of  these  two  substances.  Under 
normal  conditions  a  man  eliminates  12  to  14  of  sul- 
phuric acid,  0.3  to  0.7  of  lime,  and  0.6  to  1.0  of 
magnesia  to  100  of  nitrogen. 

The  urine,  on  leaving  the  body,  deposits  mucus  after 
a  certain  time ;  it  often  also  deposits  urates,  especially 
during-  fevers.  But  its  acidity  soon  increases,  in 
consequence  of  the  formation  of  more  uric  acid;  this 
acid  is  often  seen  to  deposit  in  the  form  of  rhomboidal 
prisms.  Other  acids  are  also  formed,  chiefly  acetic  and 
lactic  acids.  At  the  end  of  a  few  days  the  urine  loses 
its  acidity  and  becomes  decidedly  alkaline  from  the 
formation  of  a  considerable  quantity  of  ammonium 
carbonate.  This  salt  is  formed  from  the  urea  thus : — 

oo"  \  ocr(OB 

EL      N+2H.O=9(NH4)  »  L 

H!  ) 

Thip    transformation    of    urea    is    favoured   by  the 


NORMAL    CONSTITUENTS    OF    THE    URINE.  339 

presence  of  the  mucous  sediment  which  urine  deposits 
when  exposed  to  the  air,  also  by  the  action  of  beer, 
yeast,  and  albuminoid  substances. 

It  is  a  true  fermentation,  accompanied  by  the 
development  of  an  organized  vegetable  substanee 
(Torulacece),  which  reproduces  itself  by  germination. 
Often  its  action  is  impeded  by  the  formation  of  infusoria, 
which  maintain  the  acidity  of  the  urine  for  a  long 
period.  Cohn  finds  the  organisms  to  be  Micrococus  ureac. 

NORMAL    CONSTITUENTS   OF   THE   URINE. 

Of  the  solid  constituents,  urea  is  the  most  abundant. 
The  urinary  secretion  in  man  furnishes  about  30 
grammes  of  urea  in  24  hours,  but  this  quantity  may 
vary  greatly.  The  average  in  women  is  20  grammes ; 
it  falls  to  9  grammes  in  old  men.  A  very  nitrogenous 
diet  increases  it,  while  food  which  is  poor  in  nitrogen 
diminishes  it.  Urea  does  not  even  disappear  in  an 
animal  rigorously  kept  without  food ;  it  is  then  formed 
at  the  expense  of  the  tissues. 

When  the  urinary  secretion  increases,  even  though 
from  the  drinking  of  large  quantities  of  water,  the 
amount  of  urea  produced  also  increases.  It  augments 
likewise,  according  to  some  authorities,  during  severe 
physical  labour. 

We  may  admit,  in  general,  that  urea  diminishes 
when  the  circulation  of  blood  is  sluggish,  and  that  it 
increases  when  the  circulation  becomes  active. 

There  is  only  a  very  small  quantity  of  urea  in  the 


340  ANIMAL  CHEMISTRY. 

blood;  it  becomes  greater  when  the  kidneys  perform 
their  functions  badly.  Urea  is  not  formed  in  the 
kidneys.  Dumas  and  Prevost  showed  in  1823  that  the 
blood  of  animals,  from  which  these  organs  have  been 
removed,  contains  considerable  amounts  of  urea. 

This  fact  has  been  confirmed  by  Bernard  and 
Barreswil,  who  also  showed  that,  after  the  removal  of 
the  kidneys,  the  gastric  and  intestinal  secretions 
increase.  The  gastric  juice  remains  acid  but  contains 
ammonia.  When  tte  animal  becomes  entirely  ex- 
hausted, urea  is  found  in  the  blood  in  a  very  notable 
quantity. 

Picart  and  Meissner  have  obtained  the  same  results, 
which  have,  however,  been  doubted  by  Oppler,  Perls, 
and  Zalesky.  The  question  has  been  taken  up  by 
Grehant,  who  conceived  the  idea  of  determining  the 
amount  of  urea  with  the  greatest  care,  and  he  has 
perfectly  demonstrated  that  urea  accumulates  in  the 
blood  in  consequence  of  nephrotomy. 

100  grammes  of  arterial  blood  contained  : 

Urea. 

Before  nephrotomy         .         .         .  0.088  grammes. 

Three  hours  and  forty  minutes  later  0.093       „ 

Twenty-one  hours  later  .         .  0.252       „ 

Twenty-seven  hours  later        .         .  0.276       „ 

The  urea  increases,  therefore,  after  the  operation, 
and  the  increase  takes  place  in  a  continuous  manner 
proportional  to  the  time. 


tfmr  ACID.  341 

The   ligature   of  the   ureters   renders   the    kidneys 
totally  inactive,  for  the  blood  which  leaves  this  organ 
is  found  to  contain  the  same  quantity  of  urea  as  on 
entering.       Hence,    after   the  ligature  of  the  ureters, 
following  nephrotomy,  urea  accumulates  in  the  blood. 

The  amount  of  urea  excreted  by  man  represents  very 
nearly  the  whole  amount  of  nitrogenous  food  which 
has  failed  to  be  assimilated,  for  the  surplus  is  obviously 
found  in  the  excrements,  and  they  contain  very  little. 
The  urine,  therefore,  is  the  liquid  through  which  the 
nitrogen  is  eliminated,  and  the  urea  is  almost  the  sole 
agent  for  effecting  this. 

For  this  reason  the  determination  of  the  urea  is 
highly  important  as  furnishing  us  with  data  relative  to 
the  elimination  of  the  nitrogen  from  the  body. 

Urea  is  not  produced  in  the  muscles  ;  though  creatin 
is  easily  transformed  into  urea  when  out  of  the  body, 
yet,  in  spite  of  the  considerable  quantity  of  creatin 
which  exists  in  the  muscles,  no  urea  is  found  in 
muscular  tissue.  On  the  contrary,  it  is  sufficient  to 
take  in  the  food,  creatin,  gelatin,  or  analogous  matters, 
to  observe  that  the  urea  is  thereby  formed  in  greater 
quantity  in  the  mine.  It  is  therefore  rational  to 
admit  that  these  substances  are  oxidized  in  the  blood, 
and  that  their  nitrogen  is  eliminated  in  the  form  of  urea. 

URIC  ACID. — The  urinary  secretion  furnishes  each 
day  1.183  grammes  of  uric  acid  on  an  average  (Wundt). 
It  increases  during  digestion,  and  diminishes  when  the 
body  is  fatigued.  In  general  it  is  produced  whenever 
oxidation  is  impeded,  and  an  increase  in  uric  acid  is 


342  ANIMAL  CHEMISTRY. 

associated  with  a  corresponding  diminution  of  urea. 
This  acid  is  found  in  the  urine  of  persons  affected  with 
the  gout. 

Uric  acid,  urate  of  ammonia,  and  urate  of  sodium 
are  often  deposited  in  urine  a  few  hours  after  emission. 

HIPPURIC  ACID  is  found  in  small  quantity  in  human 
urine.  It  increases  with  vegetable  nourishment,  in 
diabetes,  and  in  certain  other  diseases.  It  is  formed, 
molecule  for  molecule,  when  a  benzoic  compound  is 
taken  into  the  stomach.  Lactic  acid  is  only  produced 
in  the  urine  when  digestion  and  respiration  are  im- 
paired. It  is  formed  in  fevers,  and  whenever  digestion 
and  circulation  are  impeded. 

Creatinin,  and  possibly  creatin,  exists  in  the  urine. 

An  adult  throws  off,  in  the  urinary  secretion,  about 
1.16  gr.  of  creatinin  in  twenty-four  hours.  J.  Hunk 
(60-76-1799)  finds  over  '008  per  cent,  sulphocyan- 
hydric  acid  in  normal  urine. 

Stoedler  considers  phenio  acid  and  two  ill-defined 
acids — damolic  and  damaluric  acids, — to  which  the 
odour  of  the  urine  is  supposed  to  be  due,  as  constant 
constituents  of  the  urine.  Scherer  regards  xanthin  as 
existing  normally  in  the  urine,  though  only  in  traces. 
It  is  an  amorphous  substance,  soluble  in  acids  and 
boiling  water. 

According  to  Schunck,  urine  contains  always  indican. 
This  name  is  given  to  a  body  not  as  yet  obtained  in  a 
crystalline  condition,  soluble  in  water,  alcohol,  and 
ether,  and  is  essentially  characterized  by  its  property 
of  decomposing  in  presence  of  strong  hydrochloric  acid, 


tNDIGOGEN.  348 

furnishing,    by    combining  with  water,   indigo    and   a 
saccharine  matter,  indiglucin. 


Indican  Indigo  Indigluoin 

The  formation  of  this  body  accounts  for  the  violet 
and  reddish  tints  which  are  sometimes  observed  in 
urine  undergoing  decomposition.  These  pnenomena 
take  place  only  in  the  presence  of  atmospheric  or  other 
oxygen,  as  the  indig0  blue  is  very  easily  reduced. 


Urozanthin  and  still  more  appropriately  indigoge* 
are  modern  synonyms  for  indicau. 

The  substance  which  imparts  to  urine  its  yellow 
colour  has  been  called  uroclu-oine  by  Thudicum. 
According  to  Heller,  ether  extracts  from  urine,  which 
has  been  evaporated  almost  to  dryness,  a  matter 
which  he  was  not  able  to  isolate,  and  which  he  calls 
uroxanthin.  It  is  remarkable  from  the  fact  that, 
under  the  action  ot  acids  and  in  certain  pathological 
states,  ft  is  transformed  by  oxidation  into  two  other 
substances  —  one  blue  uroglaucin,  the  other  red  urrhodin. 

Since  these  substances  have  not  been  isolated  with 
certainty,  we  shall  not  further  dwell  on  them. 

GLUCOSE.  —  Glucose  is  always  present  in  normal 
urine,  according  to  some  chemists,  though  doubted  by 
Seegen  and  Gorup-Besanez. 

The  quantity  of  sugar  present  in  normal  urine 
amounts  in  twenty-four  hours  to  1  to  1.5  grammes 


344  ANIMAL   CHEMISTRY. 

according  to  Briicke,  also  according  to  Bence  Jones. 
It  is  therefore  less  than  one-thousandth. 


FATTY    BODIES,    SALTS,    AND    GASES    IN    URINE. 

Fatty  bodies  are  found  in  the  urine,  but  their 
proportion  is  very  minute. 

The  quantity  of  saline  matter  in  the  urine  is  con- 
siderable. It  amounts  to  about  15  grammes  in  twenty- 
four  hours.  This  quantity  may  increase  to  25  grammes, 
and  decrease  to  8  grammes.  It  is  less  in  women,  and 
still  less  in  children.  Among  these  solid  matters  are 
prominently  phosphates,  sodium  phosphate,  calcium 
phosphate,  and  magnesium  phosphate.  The  quantity 
of  phosphoric  acid  eliminated  in  the  urine  varies  from 
3  grammes  to  5  grammes  in  twenty-four  hours.  This 
acid  increases  during  digestion.  It  diminishes  in  preg- 
nant women,  and  in  the  eighth  month  there  is  so  little 
that  both  its  reactions  and  those  of  calcium  are  hardly 
perceptible.  Urine  always  contains  alkaline  chlorides, 
and  chiefly  sodium  chloride.  The  quantity  increases 
as  the  amount  ingested  increases,  but  the  whole  of  this 
substance  is  not  eliminated  through  the  urine.  The 
proportion  of  chloride  increases  after  eating,  and  is  at 
its  minimum  during  the  night.  Exercise  increases  the 
amount.  The  weight  of  chlorine  evacuated  in  twenty- 
four  hours  is  about  10  grammes.  When  all  salt  is 
removed  from  the  food  the  amount  diminishes  in  the 
urine,  and  remains  fixed  at  2  to  3  grammes  per  day, 


FATTY  BODIES,  SALTS,  AND  GASES  IN  URINE.   345 

which  amount  is  derived  from  the  tissues,  and  a  rapid 
enfeeblement  results.  Sulphates  are  found  in  the 
urinary  secretion.  The  quantity  increases  during 
digestion  ;  it  averages  2  grammes  in  twenty-four  hours. 

Normal  acid  urine  contains  no  ammonium  salts,  but 
contains  them  on  becoming  alkaline,  some  time  after  its 
voidance.  The  same  is  the  case  with  the  urine  of 
herbivora,  which  is  always  alkaline. 

Many  substances  taken  into  the  body  which  do  not 
serve  as  aliments  are  found  again  in  the  urine,  in  case 
they  are  not  capable  of  uniting  with  certain  principles 
of  the  body  to  form  insoluble  compounds.  Those 
metallic  salts  are  among  these  latter,  which  form 
precipitates  with  albuminoid  substances. 

Substances  not  precipitable  in  the  organism  and 
difficultly  oxidized — such  as.  chlorides,  iodides,  sul- 
phates, nitrates,  urea,  quinine,  and  most  fragrant  and 
colouring  matters — reappear  unchanged  in  the  urine. 
Oxidizable  substances,  on  the  contrary,  undergo  the 
same  transformations  which  they  sustain  when  acted 
upon  by  oxidizing  agents.  Alkaline  sulphides  are 
converted  into  sulphates,  alkaline  organic  salts  into 
carbonates;  benzoic  and  cinnamic  acids  into  hippuric 
acid,  uric  acid  into  urea,  salicine  into  snligenin  and 
salicylic  acid.  The  oxidation  of  certain  other  matters 
is  more  complete ;  they  furnish  carbon  dioxide  and 
water,  which  are  the  ultimate  products  of  the  oxidation 
of  organic  bodies.  This  is  probably  also  what  occurs  to 
many  substances  which  never  reappear  in  tlie  urinary 
secretion,  even  after  abundant  ingestion  of  the  same ; 


346  ANIMAL    CttKMlSTRV. 

such  are  mannite,  ether,  resins,  the  colouring  matter 
of  leaves,  litmus,  cochineal,  amygdaline»  airilin, 
camphor,  etc. 

The  rapidity  with  which  these  bodies  pass  into  the 
urine  depends  upon  their  solubility.  Potassium  iodide 
is  found  in  the  urine  in  a  few  minutes  after  being 
administered.  A  longer  time  is  necessary  for  the  urine 
to  assume  the  odour  which  is  developed  after  eating 
asparagus  and  the  inhaling  of  the  vapours  of  turpentine. 

The  gases  of  tlie  urine  are  oxygen,  nitrogen,  and 
carbon  dioxide.  A  mean  of  fifteen  experiments  made 
by  Moring  gave  for  a  litre  of  fresh  urine — 

Oxygen       ...  .       0.60  o.o. 

Nitrogen     .....       7.77   „ 
Carbon  dioxide    ....     15.96   „ 

These  figures  are  probably  too  small,  as  the  method 
by  which  the  gases  were  determined  was  that  of 
Magnus. 

Walking  increases  the  amount  of  carbon  dioxide. 

Carbon  dioxide.  Nitrogen.      Oxygen. 
Urine  during  repose     .     11.877        7.494        0.493 
„      when  walking    .     22.880        8.204        0.466 

The  renal  secretion  of  ophidians  is  solid,  and  com- 
posed chiefly  of  uric  acid  ;  that  of  batrachians  is  liquid, 
and  contains  urea. 

The  urine  and  excrements  of  birds  contain  chiefly 
acid  urates,  earthy  phosphates,  and  a  small  amount  of 
ma. 


ANALYSES  OP    DIABETIC   URINE.  347 

PATHOLOGICAL  STATES. — The  urinary  secretion  in- 
creases in  certain  diseases  (diabetes,  polydipsia).  In 
the  first  case  its  density  may  increase,  as  sugar  is  often 
present  in  large  proportions ;  it  sometimes  is  as  high  as 
1.040.  In  polydipsia  the  density  falls  to  1.001.  It 
diminishes  in  cholera,  in  diseases  of  the  liver,  and  in 
fevers'. 

Diabetes. — The  quantity  of  sugar  excreted  in  the 
urine  may  amount  to  1200  to  1500  grammes  in  24 
hours. 

Bouchardat,  to  whom  we  are  indebted  for  important 
investigations  relative  to  this  disease,  has  shown  that 
the  formation  of  sugar  may  be  lessened  or  even  arrested 
by  submitting  the  patient  to  a  nourishment  devoid  of 
farinaceous  and  saccharine  matter,  by  furnishing  him 
for  example,  instead  of  ordinary  bread,  bread  made 
of  gluten  or  flour  freed  from  starch  by  washing. 

The  uric  acid  diminishes  in  quantity,  or  disappears 
in  the  urine  of  diabetic  persons. 


ANALYSES  OF   DIABETIC   URINE    BY  SIMON   AND 
BOUCHARDAT. 


Simon. 

Bouchardat. 

^^^^-« 

II. 

I. 

Density    . 

Water 

1.018 
957.00 

1.016 

960.00 

837.58 

Solid  constituents 

43.00 

40.00 

162.42 

Urea 

traces. 

7.99 

8.27 

348 


ANIMAL    CHEMISTRY. 
Simon. 


Uric  acid  . 
Sugar 

Alcoholic  extract 
Aqueous  extract 
Salts 

Phosphates    and 
mucus    .         . 
Albumen  . 
Oxide  of  iron 


I. 

traces. 
39.80 

2.10 


II. 

traces. 
25.00 

6.50 


Bouchardat. 

I. 

traces. 
134.42 

5.27 


0.52  0.80          0.24 

traces.        traces,      traces, 
traces.        traces.         0.14 

Markownikoff  (72-182-362)  finds  acetone  and  ethyl 
alcohol,  and  believes  they  are  formed  from  the  glucose 
by  fermentation. 

Claude  Bernard  has  shown  that  diabetes  can  be 
produced  artificially  by  puncturing  the  "  fourth 
ventricle." 

A  slow  poisoning  of  frogs  with  curari,  the  slow 
action  of  strychnia,  the  destruction  of  the  spinal 
column  of  frogs,  etc.,  produce  diabetes.  Artificial 
diabetes  is  dependent  upon  the  liver,  as  this  state  can 
never  be  obtained  in  a  frog  from  which  the  liver  has 
been  removed.  Sai'kowsky  has  shown  that  if  the  for- 
mation of  glycogenous  matter  in  the  liver  of  a  rabbit 
be  arrested,  a  result  which  is  easily  produced  by  the 
action  of  arsenates,  this  animal  cannot  become  diabetic 
neither  by  curari  nor  by  puncturing  the  fourth 
ventricle. 

F.  W.   Pavy  (112-23-59;  24-51)   obtains  diabetes 


OTHER    ABNORMAL    STATES    OF    THE    URINE.          349 

artificially  in  dogs  by  passing  defibrinated  arterial 
blood  through  the  liver  ;  saliva  used  instead  of  blood 
produced  no  glycosuria.  Upon  inhalation  of  oxygen 
Pavy  noticed  a  like  appearance  of  sugar  in  the  urine. 

ALBUMINURIA. — Albumen  does  not  exist  normally 
in  the  urine.  When  it  is  found,  it  is  due  either  to  the 
secretion  of  an  albuminous  urine  by  the  kidneys,  or 
to  an  admixture  of  blood,  pus,  or  lymph. 

Albuminous  urine  is  pale,  acid,  opaline,  often  of  a 
density  less  than  normal,  As  much  as  20,  30  and  even 
35  grammes  have  been  found  to  have  been  secreted  in 
twenty-four  hours. 

The  albumen  increases  after  taking  food  ;  it  is  at  its 
minimum  during  the  night.  It  increases  with  nitro- 
genous food. 

According  to  Lehman  this  albumen  exists  in  two 
states,  one  part  is  the  modification  of  albumen  called 
metaglobuline  and  paraglobuline,  and  is  precipitable  by 
carbon  dioxide.  The  other  remains  in  the  liquid  after 
the  passage  of  the  gas,  and  is  precipitated  by  ordinary 
acids. 

ANAEMIA. — The  urine  is  pale  and  scarcely  acid  in 
anaemic  persons ;  it  sometimes  even  becomes  alkaline. 
It  is  rich  in  salts  and  poor  in  most  organic  con- 
stituents. 

OTHER  ABNORMAL  STATES  OF  THE  URINE. — The 
urinary  secretion  decreases  considerably  in  fevers,  and 
is  of  a  deeper  colour  and  more  dense  than  normal  urine. 
Its  acidity  increases  on  account  of  the  uric  acid  which 
forms  abundantly,  and  of  the  lactic  acid  which  is  also 


860  ANIMAL   CHEMISTRY. 

developed.  The  urea  disappears  in  about  the  inverse 
proportion.  The  extractive  matters  increase ;  the  salts, 
and  especially  the  sodium  chloride,  decrease. 

The  proportion  of  urea  increases  in  intermittent 
fevers,  also  at  the  commencement  of  typhoid  fever. 

The  quantity  of  urea,  and  especially  that  of  uric 
acid,  increases  in  inflammatory  diseases.  At  the  com- 
mencement of  acute  attacks  the  urea  has  been  observed 
to  amount  to  60  grammes.  The  urine  of  persons  affected 
with  phthisis  is  richer  in  uric  acid  than  normal  urine, 
and  fatty  substances  are  also  observed  in  it. 

The  urea  diminishes  in  nervous  affections. 

In  scarlatina  and  small-pox  the  urine  contains  am- 
monia, although  it  retains  its  acid  reaction. 

A.  Pohl  found  cholesterin  (40-76-737)  in  the  urine 
of  an  epileptic  patient  who  had  taken  large  doses  of 
potassium  bromide. 

Epithelial  cells  are  found  in  large  quantities  m  the 
urine  in  erysipelas,  in  scarlatina,  in  the  commencement 
of  Bright's  disease,  and  in  different  urinary  affec- 
tions. 

Fibrin  and  blood-globules  appear  in  the  urine  during 
inflammation  of  the  genital  and  urinary  organs.  In 
catarrh  and  in  paralysis  of  the  bladder  the  urinary 
secretion  contains  urate  of  ammonium.  The  urine  is 
decomposed  in  the  body  of  persons  affected  with  catarrh 
of  the  bladder ;  and  in  the  urine  are  observed  monads, 
vibrions,  and  mycodenns. 

Mucus  is  present  in  small  quantity  in  normal  urine. 
In  various  diseases  of  the  genito-urinal  organs,  the 


OTHER   ABNORMAL    STATES    OF    THE    T7RINB. 

mucus  increases  to  such  an  extent  as  to  render  the 
urine  turbid  or  milky. 

Pus  is  found  in  the  urine  when  suppuration  is  esta- 
blished in  the  genito-urinal  tract. 

The  urine  in  jaundice  contains  the  acids  and  colour- 
ing matters  of  the  bile.  These  acids  also  pass  into 
the  urine  in  pneumonia.  The  bile  itself  is  often  found 
in  the  urine,  and  in  this  case  boiling  ether  agitated 
with  the  urine  takes  on  a  green  colour. 

The  urinary  secretion  diminishes  or  ceases  entirely 
in  cholera. 

The  proportion  of  phosphates  increases  in  nervous 
affections.  The  quantity  of  chlorine  decreases  chiefly  in 
pneumonia,  in  obstinate  diarrhoea,  and  during  cholera. 

Chyle  and  casein  are  found  in  certain  urines. 

The  urine  is  brown  in  acute  rheumatism ;  it  is  red  in 
many  diseases  in  which  the  colouring  matter  of  the 
blood  passes  into  the  urine ;  it  is  almost  colourless  in 
megrim  and  in  nervous  affections. 

Von  Merling  and  Musculus  (60-1875-662)  have 
examined  the  urine  of  a  person  who  for  a  long  time 
took  5  to  6  grammes  of  chloral  hydrate  every  evening. 
The  urine  had  an  acid  reaction,  reduced  alkaline  copper 
solutions,  contained  neither  chloroform,  formic  acid,  nor 
sugar,  but  it  contained  chloral  hydrate  in  small 
quantity,  and  turned  the  plane  of  polarization  to  the 
left ;  this  latter  property  was  due  to  an  acid  which  they 
called  urochloral  acid,  obtained  by  evaporating  the  urine 
acidified  with  sulphuric  acid,  and  extracting  the  acid 
with  a  mixture  of  alcohol  and  ether.  This  new  acid 


362  ANIMAL   CHEMISTRY..     . 

crystallizes  in  colourless  silken  needles,  dissolves  in 
water,  alcohol,  and  a  mixture  of  alcohol  and  ether,  but 
is  insoluble  in  pure  ether ;  with  potassium,  sodium, 
barium,  and  copper  it  gives  well  crystallized  salts ;  its 
composition  is  expressed  by  the  formula  C7H12C1206. 

F.  Baumstark  (60-1874-1170)  found  in  the  urine  of 
a  person  suffering  with  leprosy  two  peculiar  colouring 
principles  which  he  calls  urorubrohematin  and  uro- 
fuchsohematin.  Urorubrohematin  is  a  light  bluish-black 
mass,  insoluble  in  water,  alcohol,  ether,  chloroform,  or 
a  solution  of  salt,  soluble  in  alkalies,  ammonium 
hydrate,  alkaline  phosphates  and  carbonates,  alcohol 
containing  acids,  difficultly  soluble  in  dilute  sulphuric 
acid,  and  solutions  of  salt  acidified  with  hydrochloric 
acid.  The  acid  solution  shows  a  characteristic  absorp- 
tion spectrum.  The  formula  obtained  by  analysis  is 
OggH^NgFegOgg  (?).  Urofuchsohematin  is  black,  pitchy, 
insoluble  in  water,  alcohol,  ether,  chloroform,  acids,  or 
acidified  or  non-acidified  salt  solutions  ;  it  is  soluble  iu 
alkalies,  ammonium  hydrate,  alkaline  phosphates  and 
carbonates,  and  acidified  alcohol.  Analysis  shows  its 
formula  to  be  C68H10GN8026  (?). 

J.  Miiller  (60-1874-1526)  found  in  the  urine  of  a 
child  pyrocatechin. 

URINARY  SEDIMENTS. — Human  urine  abandoned  to 
itself  often  deposits  solid  crystalline  bodies.  During 
fever,  urate  of  sodium  is  observed  to  form  a  short  time 
after  emission.  These  crystals  are  microscopic,  and  the 
appearance  of  the  deposit  is  corpuscular  and  colourless. 


UBINARY    CALCULI.  353 

They  axe  recognized  by  their  disappearance  when  the 
urine  is  heated. 

The  urine  sometimes  deposits,  three  or  four  hours 
after  emission,  prismatic  crystals  of  uric  acid  having  a 
rhombic  base. 

When  ammoniacal  fermentation  takes  place  in  urine, 
a  deposit  of  urate  of  ammonium  is  observed  mingled 
with  calcium  phosphate  or  carbonate  and  ammonio- 
magnesium  phosphate.  This  sediment  forms  whitish 
opaque  grains,  insoluble  in  water,  soluble  in  acetic  acid, 
and  insoluble  in  ammonia. 

At  other  times,  crystals  of  calcium  oxalate  i:&i\ 
ammonio-magnesium  phosphate  separate  out. 

C.  Stein  (1-187-99)  finds  in  certain  rare  cases  in 
which  the  urine  is  alkaline  that  magnesium  phosphate 
occurs  in  the  sediment. 

There  also  separates  out  from  the  urine,  under 
unusual  and  not  well  understood  circumstances,  an 
organic  matter  called  ct/xtin,  containing  sulphur. 

This  substance  is  colourless,  insoluble  in  hot  water, 
and  soluble  in  ammonia. 

Besides  these  crystalline  substances,  the  urine  de- 
posits organized  matters  ;  mucus  is  alway  present  in 
it,  sometimes  pus,  spermatozoids,  blood  globules,  and 
coagulated  albumen. 

URINARY  CALCULI. — This  name  is  given  to  concre- 
tions of  solid  substances  which  form  in  the  bladder. 
At  times  they  escape  with  the  urine  in  small  grains  or 
powder ;  they  are  then  known  as  gravel. 


•354  ANIMAL    CHEMISTRY. 

These  deposits .  are  formed  of  various  substances  : 
uric  acid,  urate  of  sodium  or  ammonium,  calcium  car- 
bonate, oxalate  or  phosphate,  ammonio- magnesium 
phosphate,  cystin  or  xanthic  oxide. 

The  cystin  may  be  obtained  by  treating  the  calculi 
with  sodium  carbonate  and  adding  acetic  acid  to  the 
liquid,  when  it  deposits  cystin  in  handsome  hexagonal 
plates. 

This  substance  may  also  be  obtained  from  the 
kidneys. 

A  cystin  calculus  is  soluble  in  caustic  alkalies,  and 
even  in  solutions  of  alkaline  carbonates,  with  the  ex- 
ception of  ammonium  carbonate.  It  is  dissolved  by 
the  mineral  acids,  and  precipitated  by  acetic  acid. 
Heated  in  the  air,  it  furnishes  sulphurous  oxide. 
Heated  with  an  alkali  it  furnishes  a  sulphide. 

The  nature  of  the  calculi  formed  of  cystin  will  be 
described  further  on. 

ANALYSIS    OF     URINARY    C A  LCU  J.US. 

Urate  of  sodium          ....  9.77 

Calcium  phosphate     ....  34.74 

Ammonio- magnesium  phosphate          .  88.35 
Calcium  carbonate      .         .         .         .3.14 

Magnesium  carbonate         .          .          .  '2.55 

Albumen  .          .          .          .          .  b'.87 

Water  and  loss  .  J-.58 


100.00 

(Lindbergson.) 


ANALYSIS   OF    A   CYSTIN    CALCULUS.  355 


ANALYSIS  OF   A    FERRUGINOUS   URINARY   CALCULUS. 


Ferric  oxide 
Alumina  . 
Silica 
Calcium    . 
Water      . 
LOBS. 


100.00 
(Boussiiigault.) 


ANALYSIS   OF    A   CYSTIN   CALCULUS. 

Cystin 97.5 

Calcium  phosphate  and  oxalate  .         .         2.5 

100.0 
(Lassaigne.) 


356  ANIMAL    CHEMISTRY. 


ANALYSIS   OF  URINE. 

THE  whole  of  the  urine  voided  during  24  hours  is  col- 
lected and  its  volume  measured  ;  of  this  250  grammes  are 
taken  and  allowed  to  stand  for  24  hours ;  or  the  urine  first 
voided  in  the  morning  after  sleep  is  taken  for  analysis. 

We  commence  by  determining  by  means  of  litmus 
paper  the  reaction  of  this  urine,  and  then  determine  its 
density  ;  as  the  presence  of  water  or  albumen  diminishes 
its  density,  while  the  presence  of  sugar  and  salts 
augments  it.  There  are  used  for  this  test  special 
areometers  or  hydrometers,  called  urinometers.  It  is 
well  to  verify  once  for  all  the  graduation  of  these 
instruments  by  means  of  urines  whose  specific  gravity 
has  been  determined  by  the  ponderal  method. 


GKLUCOSK. 

We  have  already  stated  that  abnormal  urine  may 
contain  very  large  proportions  of  sugar  :  such  urine  is 
usually  Bweet  and  denser  than  ordinary  urine.  It  is 
susceptible  of  fermentation,  turns  the  plane  of  polari/a- 
tion  to  the  right,  and  is  but  slightly  coloured. 


Q 

QUANTITATIVE    ANALYSTS    OF    URINE. 

If  it  is  desired  to  extract  the  sugar,  basic  lead  acetate 
is  added  in  excess,  the  solution  filtered,  the  excess  of 
lead  precipitated  by  hydrogen  sulphide,  again  filtered, 
and  evaporated  until  it  crystallizes. 

THE  QUALITATIVE  TESTS.— Its  presence  merely  may 
be  detected  by  the  tests  given  on  page  187. 

It  should,  however,  be  remarked  that  these  reactions 
are  not  reliable  unless  a  precipitate  appears  within  one 
or  two  minutes  boiling,  as  secondary  reactions  are 
produced  with  the  other  substances  contained  in  the 
urine. 


QUANTITATIVE    DETERMINATION    OF    THE    SUGAR    BY    THE 
REDUCTION    OF    COPPER    SALTS. 

PREPARATION  OF  THE  LIQUID. — Weigh  out  200  gr. 
of  pure  E-ochelle  salt,  which  place  in  a  flask  graduated 
to  1  litre  ;  add  500  c.c.  of  a  solution  of  sodium  hydrate 
of  24°  Baume"  (D  =  1.199),  or  600  c.c.  of  a  solution 
22°  Baume  (D  =1.180).  The  solution  is  facilitated  by 
agitating  and  slightly  heating  in  a  water  bath. 

In  another  vessel  dissolve  36.46  gr.  of  commercial 
copper  sulphate,  which  has  been  purified  by  two  or 
three  recrystallizations,  in  140  c.c.  of  distilled  water, 
slightly  heating.  This  solution  is  slowly  poured  into 
the  first,  stirring  at  the  same  time,  that  the  precipitate 
may  be  dissolved.  Rinse  out  the  vessel  which  con- 
tained the  copper  sulphate  two  or  three  times,  and  after 


358  ANTMAI.    CHEMISTRY1. 

placing  the  litre-flask  in  a  vessel  of  cold,  common 
water,  add  enough  distilled  water  to  bring  the  liquid  in 
the  flask  up  to  1  litre.  This  solution  is  very  reliable,  and 
may  be  preserved  for  months  exposed  to  the  light  with- 
out alteration.  For  an  improved  reagent,  see  p.  187. 

Each  10  c.c  corresponds  to  0.050  gr.  of  pure  cane 
sugar,  or  0.0526  gr.  of  pure  glucose. 

The  determination  is  made  by  placing  20  c.c  of  the 
cupro-alkaline  solution  in  a  porcelain  dish,  bringing 
the  same  to  boiling,  and  adding  gradually — at  the  same 
time  agitating  with  a  glass  rod — the  saccharine  urine 
from  a  burette  graduated  to  tenths  of  a  cubic  centimetre. 
There  is  first  formed  a  yellowish,  then  a  red  precipitate. 
When  the  colour  appears  constant  remove  it  from  the 
flame  ;  the  supernatant  liquid  soon  becomes  clear ;  if 
it  should  appear  greenish,  again  heat  and  add  more  of 
the  urine  drop  by  drop.  The  liquid  must  be  neither 
greenish  nor  yellow.  As  long  as  there  is  any  copper 
in  the  solution  a  drop  of  urine  will  produce  an  orange- 
coloured  ring  when  it  falls  into  the  reagent.  The 
amount  of  urine  necessary  to  effect  this  will,  of  course, 
be  an  amount  containing  2  x  0.0526  or  0.1052  gr.  of 
glucose. 

DETERMINATION  OF  GLUCOSE  IN  THE  URINE,  by 
means  of  lead  acetate. — In  clinical  experiments  it  is 
often  sufficient  to  add  to  the  urine  a  few  drops  of  a  con- 
centrated solution  of  lead  acetate,  separate  the  precipi- 
tate formed  by  filtering,  and  after  bringing  the  filtrate 
to  a  known  volume  employ  it  in  the  same  manner  as  the 
urine  in  the  preceding  operation. 


ANALYSIS    OF    TJRINK — ALBUMEN.  359 

The  lead  salt  has  the  effect  of  precipitatiug  the 
foreign  matter.  The  glucose  is  not  precipitated  by  the 
acetate  unless  ammonium  hydrate  is  added. 

When  diabetic  urine  is  highly  charged  with  sugar  it 
must  be  diluted  with  5,  10,  or  20  times  its  volume  of 
water. 

Grlucose  can  also  be  determined  by  adding  yeast  to 
the  urine,  and  from  the  loss  of  carbonic  acid  in  the 
resulting  fermentation  calculating  the  glucose  present. 
It  can  also  be  estimated  by  means  of  a  polarizing  appa- 
ratus, such  as  is  used  for  determining  the  strength  of 
saccharine  solutions  for  sugar  refineries. 

As  it  is  not  within  the  scope  of  this  work  to  supply 
elaborate  instructions  with  regard  to  urine  analysis, 
those  desiring  full  details  regarding  the  examination  of 
urine  for  this  or  other  constituents  should  consult  some 
author  on  chemical  analysis,  or  specifically  on  the 
chemical  examination  of  the  urine.  A  liberal  amount 
of  laboratory  work  is  requisite,  however,  for  such  as 
would  acquire  a  practical  ncquairitanee  with  the 
chemistry  of  abnormal  urine. 


ALBUMEN. 

Albumen  is  coagulated  by  heat  and  nitric  acid.  It 
is  necessary  to  have  recourse  to  these  two  reactions  to 
detect  with  certainty  the  presence  of  albumen  in  urine. 
In  fact,  by  simply  heating-  the  urine  it  often  becomes 
turbid,  owing  to  the  precipitation  of  the  earthy  phoe- 


360  ANIMAL    OHKMISTRY. 

phates  or  carbonates;  these  salts  may  be  recognized, 
however,  by  adding  a  drop  or  two  of  nitric  acid,  which 
will  redissolve  the  precipitate  formed.  On  the  other 
hand,  nitric  acid  will  produce  a  white  precipitate  in  the 
urine  of  a  patient  who  has  been  taking  various  resinous 
remedies. 

When  it  has  been  found  that  four  to  five  cubic  cen- 
timetres of  urine  coagulates  on  heating,  and  that  it 
continues  to  coagulate  after  adding  eight  to  ten  drops 
of  nitric  acid,  we  may  conclude  that  this  urine  contains 
albumen. 

In  order  to  estimate  the  amount  of  albumen  we  com 
mence  by  ascertaining  whether  the  urine  is  alkaline  or 
not ;  in  case  it  is,  it  should  be  slightly  acidulated  with 
acetic  acid.  100  c.c.  of  the  urine  are  taken  and  heated 
so  as  to  cause  coagulation — that  is,  until  the  urine  just 
commences  to  boil.  The  liquid  is  then  thrown  upon  a 
double  filter,  i.e.,  two  filters  of  equal  size  and  weight 
placed  one  within  the  other.  The  albumen  remains 
upon  the  inner  filter;  it  is  washed  with  water,  then 
with  alcohol,  and  when  it  has  well  drained  the  two 
filters  are  dried  at  110°.  The  difference  between  the 
weight  of  the  filters  with  the  precipitate  and  the  filters 
empty  is  the  weight  of  the  albumen. 

Another  determination  to  check  the  first  may  be 
made,  precipitating  the  albumen  with  dilute  nitric 
acid. 


DETERMINATION    OF    UREA BILE.  361 


UREA. 

We  have  already  mentioned  the  importance  of  noting 
the  variations  in  the  amount  of  urea,  since  these  varia- 
tions give  us  light  upon  certain  points  in  the  process  of 
nutrition.  In  order  to  ascertain  whether  a  given  urine 
is  very  rich  in  urea,  a  few  drops  are  placed  on  a  watch- 
glass  with  an  equal  volume  of  nitric  acid  and  the  glass 
floated  on  cold  water ;  after  a  few  minutes  crystals  of 
nitrate  of  urea  are  to  be  seen. 

In  order  to  determine  the  amount  of  urea,  Leconte's 
method  may  be  employed,   which  is  based  upon  the 
oxidation  of  the  urea  by  hypochlorites : — 
CH4N20  +  SNaCIO  =  3NaCl  +  C02  +  2H20  +  N2. 

Carbon  dioxide  and  nitrogen  are  disengaged :  the 
former  is  absorbed  by  a  solution  of  sodium  hydrate, 
and  the  latter  collected  and  measured ;  from  the  volume 
obtained  the  amount  of  urea  can  be  determined. 


BILE. 

I.  Gives  with  sub-acetate  of  lead  a  greenish-yellow 
precipitate. 

II.  Gives  with  a  drop  of  nitric   acid,  green,  blue, 
yellow,  violet,  and  red  coloration. 

III.  Gives   with    a   solution  of    white   of    egg,  on 
adding  nitric  acid,  a  precipitate  which  is  bluish-green ; 
whereas  in  the  absence  of  bile  it  is  white. 


362  ANIMAL    CHEMISTRY. 

IV.  Yields  with  tincture  of  iodine  a  green  colora- 
tion. 

According  to  W.  G.  Smith  (7-[3]8-299)  this  reac- 
tion distinguishes  bile  from  the  so-called  indican. 


URIC    ACID 

Is  recognised  qualitatively  by  the  test  given  on  page 
125.  It  is  usually  determined  quantitatively  by 
adding  to  a  given  amount  of  urine — not  less  than 
150  to  200  c.cm. — sufficient  hydrochloric  acid  to  fully 
precipitate  the  uric  acid,  and  allowing  the  liquid  to 
stand  for  twenty-four  to  thirty-six  hours.  Traces  of 
uric  acid  still  remain  in  solution  which,  however, 
according  to  Neubauer,  are  compensated  for  by  the 
amount  of  the  urine  pigment  which  also  falls  with  the 
uric  acid.  The  precipitate  is  filtered  off,  washed,  dried, 
and  weighed. 

URATES. 

The  urates  of  sodium  and  ammonium  are  among  the 
constituents  of  normal  urine ;  they  are  often  deposited 
after  voidance  when  the  urine  has  become  cold ;  a 
deposit  is  then  observed  which  disappears  on  slightly 
heating.  These  urates  may  be  recognized  by  charac- 
teristics which  will  be  given  under  Urinary  Deposits. 


INORGANIC   SALTS    IN    URINE.  363 


HIPPURIC    ACID. 


If  hippuric  acid  is  found  to  exist  in  notable  quan- 
tities in  urine,'  it  may  be  determined  by  the  method 
already  given  under  the  general  discussion  of  this  acid. 

CREATININ. 

Oreatinin  may  be  detected  and  even  quantitatively 
determined  by  the  following  method:  Milk  of  lime, 
then  calcium  chloride,  is  added  to  300  to  500  c.c.  of 
urine  until  a  precipitate  no  longer  occurs ;  after  being 
allowed  to  stand  for  a  few  houra  the  solution  is  filtered 
and  the  filtrate  evaporated  in  a  water-bath  to  the  con- 
sistency of  a  syrup ;  40  c.o.  of  90  per  cent,  alcohol  is 
then  added,  and  the  whole  allowed  to  digest  for  twenty- 
four  hours.  The  clear  liquid  is  decanted  off,  and  a  solu- 
tion of  zinc  chloride,  as  nearly  neutral  as  possible,  is 
added.  A  compound  of  zinc  chloride  aud  creatinin  is 
formed,  which  is  collected  on  a  filter,  washed  with  quite 
cold  water,  and  dried. 

INORGANIC    SALTS. 

The  amount  of  salts  in  urine  may  be  determined  by 
evaporating  5  to  10  grammes  in  a  porcelain  dish.  The 
residue  is  ignited  at  a  slightly  elevated  temperature 
and  weighed. 

The  chlorides,  sulphates,  phosphates,  lime,  etc.,  may 
be  determined  by  the  methods  usually  employed  in 
inorganic  quantitative  analysis. 


364  ANIMAL    CHEMISTRY. 


URINARY    DEPOSITS. 

IF  the  urine  has  produced  a  deposit,  its  nature  may 
be  determined  by  plunging  one  end  of  a  glass  tube, 
which  has  been  drawn  out  to  a  point,  down  into  the 
deposit,  the  other  end  being  closed  by  the  finger ;  the 
finger  is  then  removed,  a  quantity  of  the  deposit 
allowed  to  ran  into  the  tube,  the  finger  replaced,  and 
the  tube  withdrawn.  A  certain  quantity  of  the  deposit 
i^  thus  obtained,  which  may  bf>  tested  with  different 
reagents  and  examined  under  the  microscope. 

Urine  which  contains  an  excess  of  uric  acid  is  acid 
and  limpid ;  the  deposit  is  then  crystalline  and  slightly 
coloured,  and  is  soluble  in  potassium  or  sodium  hydrate, 
insoluble  in  ammonium  hydrate  or  acetic  acid.  Nitric 
acid  imparts  a  darker  colour  to  urine  rich  in  uric  acid ; 
a  brown  deposit  may  also  be  formed,  wiiich  is  soluble 
in  alkalies. 

Urine  containing  u  rates  becomes  turbid  shortly  after 
voidance ;  this  deposit  is  white,  or  coloured  and  muddy. 
On  heating  it  dissolves,  as  well  as  by  adding  potassium 
or  sodium  hydrate.  Sometimes  this  deposit  is  coloured. 

Urine  containing  earthy  phosphates  may  become 
turbid,  but  this  deposit  cannot  be  confounded  with  the 
preceding,  as  it  does  not  dissolve  on  heating,  is  soluble 
in  acetic  acid,  while  not  soluble  in  potassium  or  sodium 
hydrate. 

Urinary  deposits  formed  of  calcium  oxalate  are  white; 


URINARY    DEPOSITS.  365 

they  are  insoluble  in  ammonium  hydrate  and  aoetic 
acid ;  they  also  do  not  dissolve  on  heating,  but  are 
soluble  in  mineral  acids.  If  the  deposit  were  formed 
of  calcium  carbonate,  it  would  dissolve  in  acetic  acid 
with  the  disengagement  of  carbon  dioxide.  Deposits 
of  ammonia-magnesium  phosphat  are  white ;  soluble  in 
acetic  acid,  insoluble  in  ammonium  hydrate. 

Urine  containing  cystin  has  an  acrid  and  even 
repulsive  odour.  It  furnishes  a  deposit  which  does 
not  dissolve  on  heating,  and  is  soluble  in  ammonium 
hydrate. 

Certain  urines  become  turbid  on  account  of  the 
mucus  they  contain,  or  because  decomposition  has  set 
in.  The  presence  of  blood  renders  the  urine  red,  the 
presence  of  bik  greenish.  Urines  are  sometimes  met 
with  which  are  whitish  or  opalescent;  agitation  with 
ether  renders  them  clear.  Blue  and  blackish  urines 
also  occur. 

If  a  drop  or  two  of  a  urinary  deposit  is  viewed 
through  a  microscope  magnifying  250  diameters,  and 
the  preceding  reactions  employed,  they  will  appear 
mucK  more  distinct.  We  would,  however,  add  the 
following  : 

Uric  acid  occurs  in  crystalline  plates  of  a  diamond 
shape ;  their  angles  are  often  rounded  off.  These 
plates  are  often  isolated,  sometimes  united  in  the  form 
of  rosettes  and  stars,  and  rarely  in  the  form  of  needles. 
The  urates  are  sometimes  amorphous,  sometimes 
crystalline.  Deposits  of  urates  may  be  distinguished 
from  those  of  uric  acid  by  their  solubility  in  hot 


366 


ANIMAL    CHEMISTRY 


water.  They  are  generally  found  when  the  urine  is 
alkaline. 

Crystals  of  urates,  heated  with  a  small  quantity  of 
nitric  acid,  give  a  residue  of  uric  acid.  More  nitric 
acid  forms  alloxan,  as  do  deposits  of  uric  acid,  and 
this  yields  a  characteristic  red  colour  with  ammonium 
hydrate. 

Calcium  phosphate  is  amorphous. 

Ammoiiio- magnesium  phosphate  occurs  in  prismatic 
crystals. 

Calcium  oxalate  crystallizes  in  regular  octahedrons. 

Cystiu,  C3HrNS02,  occurs  in  beautiful  hexagonal 
plates.  It  is  obtained  by  treating  the  deposit  with 
ammonium  hydrate,  and  allowing  the  liquid  to  stand ; 
the  cystin  separates  out,  and  by  the  aid  of  the  micro- 
scope the  form  of  the  crystals  may  be  distinctly  seen. 
Under  these  conditions  the  uric  acid  would  not  dis- 
solve, a  fact  which  permits  of  distinguishing  between 
deposits  of  cystin  and  those  of  uric  acid.  Cystin  is 
neutral,  insoluble  in  water,  alcohol,  ether,  or  acetic 
acid.  It  is  soluble  in  the  mineral  acids,  also  in  oxalic- 
acid.  Ignited  on  platinum  foil,  it  gives  off  an  allia- 
ceous odour.  It  is  coloured,  like  iiric  acid,  upon 
treatment  with  nitric  acid  and  ammonium  hydrate. 
It  dissolves  in  alkaline  solutions.  Heated  with  potas- 
sium or  sodium  hydrate  in  presence  of  lead  oxide,  it 
blackens  on  account  of  the  formation  of  lead  sulphide. 
Cystin  is  of  rare  occurrence,  and  its  physiological 
and  chemical  relations  have  not  linen  fully  studied. 
Loebisch  (1-182-231)  has  shown  that  no  diminution 


TTHINARY   CALCULI.  367 

of  urea  or  uric  acid  occurs  in  cases  of  cistmuria. 
though  earlier  investigators,  and  recently  also  Nieman 
; i-187-101),  have  come  to  the  conclusion  that  uric 
acid  at  least  decreases.  Nieman  established  in  the 
same  research  that  there  is  no  change  in  amount  of 
sulphur  in  urine  by  reason  of  the  presence  of  cystin. 

Pus  may  be  recognized  by  the  spherical  globules,  in 
which  two  or  three  nuclei  are  observed,  on  the  addition 
of  acetic  acid.  This  matter  is  converted  into  a  jelly- 
iike  mass  in  contact  with  potassium  or  sodium  hydrate. 

Mucus  may  be  distinguished  by  its  ropy  consistency 
and  its  coagulation  with  acetic  acid  ;  various  kinds  of 
cells  are  observed  floating  in  the  liquid.  In  these 
deposits  epithelium  cells  are  almost  always  found ;  they 
are  oval  or  irregular. 

We  also  find  in  urinary  deposits  : 

Blood  Globules. — If  the  urine  remains  acid,  they 
appear  as  quite  characteristic  discs ;  if  the  urine 
becomes  alkaline,  they  are  destroyed. 

Tube  Casts. — These  may  be:  epithelial,  fibrinoua,  mu- 
cous hyalin,  (or  colloid)  and  amyloid. 

The  first  have  special  diagnostic  importance  in  diseases 
of  the  kidneys.  These  casts  are  generally  nearly  straight, 
though  sometimes  curvilinear,  and  not  unfrequently  are 
difficult  to  find.  The  epithelial  cells  which  cover  them 
are  nearly  normal  in  appearance. 

Epithelial  Cells. — These  may  originate  from  the  kidney, 
the  bladder,  the  ureters,  or  the  canal  of  the  urethra. 

Vibrions. — Linear  in  form,  and  exhibiting  character- 
istic movements. 


368  ANIMAL    CHEMISTRY. 

TJEINAET    CALCULI. 

PHYSICAL  ASPECT. — 1.  Uric  Acid. — Form,  round: 
colour,  brown  or  reddish  ;  fracture,  earthy  or  partially 
crystalline.  When  sawn  through,  a  powder  is  obtained 
resembling  the  sawdust  of  wood. 

2.  Urate   of  Ammonium. —  These   calculi  are  small, 
and  of  a  clay  or  ash  colour,  with  an  earthy  fracture. 
They  are  formed  in  concentric  layers. 

3.  Cystin.  —  These     calculi    are    voluminous,    pale 
yellow,    rounded    in    form,    glossy,    crystalline,    and 
sometimes  striated. 

4.  Calcium  Oxalate. — Calculi  of   this   substance  are 
called  mulberry  calculi,  from  their  resemblance  to  the 
fruit  of  the  mulberry-tree,  their  surface  being  covered 
with  rounded  tubercles.    They  are  usually  grey,  though 
sometimes   dark   brown,  which    colour  is  due    to   the 
organic   matter    which  covers  them.       Their  fracture 
usually  is  granular,  sometimes  crystalline. 

5.  Ammonia-magnesium  Phosphate. — These  calculi  are 
white,  crystalline,  semi-transparent,  covered  with  small 
brilliant  crystals  ;  they  are  very  easily  pulverized. 

6.  Calcium    Phosphate. — These     calculi     are    white, 
amorphous,  and  formed  in  concentric  layers. 

The  following  table  indicates  in  brief  the  method  to 
be  followed  in  examining  different  calculi.  We  should 
mention,  however,  that  calculi  are  not  always  composed 
of  a  single  substance  ;  they  are  quite  frequently  formed 
of  several  compounds.  This  table  of  reactions  applies 
as  well  to  urinary  deposits. 


CHEMICAL    EXAMINATION. 


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370  ANIMAL    CHEMISTRY. 

CUTANEOUS    SECRETIONS    OR   TRANSPIRATIONS. 

We  include  under  this  head  the  products  of  the 
sebaceous  follicles,  of  the  glands  of  Meibomus,  and  the 
wax  of  the  ears. 

These  contain  an  albuminoid  substance,  of  which 
but  little  is  known,  neutral  fatty  bodies  (stearin,  olein), 
epidermic  cells,  and  epithelium  and  other  cells,  sodium 
chloride,  ammonium  chloride,  and  alkaline  and  earthy 
phosphates. 

SWEAT. 

The  quantity  of  this  secretion  has  not  yet  been 
determined.  It  is,  however,  known  that  it  is  quite 
large,  and  it  is  believed  to  be  more  than  half  of  that 
of  the  pulmonary  exhalations. 

It  is  obtained  by  pressing  sponges  against  the  skin 
while  in  perspiration,  and  afterwards  washing  these 
sponges  with  water.  • 

Sweat  is  an  acid  liquid,  of  an  odour  variable  with 
individuals,  and  of  a  saline  taste.  It  leaves  1  to  2.5 
per  cent,  of  fixed  substances  on  evaporation  at  100°. 
Sodium  chloride,  mixed  with  potassium  chloride,  forms 
two-thirds  of  this  residue.  Alkaline  phosphates  have 
not  been  found  in  it.  Its  acidity  is  due  to  acids  of  the 
fatty  series  ;  the  most  abundant  is  formic  acid  associated 
with  small  quantities  of  acetic  and  lactic  acids.  Favre 
has  detected  in  it  the  existence  of  a  special  acid — 
sudoric  acid. 

Sweat    contains    fatty    matters    derived     from    the 


SPERMATIC    FLUID,    OR   SEMEN.  371 

sudorific  and  sebaceous  glands  and  a  nitrogenous  sub- 
stance (possibly  urea),  which  readily  changes  into  am- 
moniacal  salts.  In  uraemia,  the  perspiration  of  the 
face  contains  a  considerable  quantity  of  this  substance. 
The  sweat  appears  milky,  on  account  of  the  epithelial 
cells  with  which  it  is  charged.  It  contains  nitrogen 
and  carbon  dioxide  gases. 


THE    SPERMATIC    FLUID,    OR    SEMEN, 

Is  viscid,  opaque,  heavier  than  water,  and  possesses 
a  marked  odour.  Heat  does  not  coagulate  it.  It 
is  precipitated  by  alcohol  and  acids. 

It  is  formed  of  a  colourless  fluid,  in  which  float  a 
large  number  of  very  minute  bodies,  called  spermato- 
zoids.  In  man  they  have  a  flattened  or  oval  body,  to 
which  is  joined  a  long  filiform  "  tail." 

The  movements  are  principally  executed  by  the  tail, 
which  has  a  sort  of  vibratile  uiidulatory  motion. 

The  seminal  liquid  gelatinizes  after  emission.  This 
effect  is  attributed  to  an  albuminoid  matter  called 
spermatin,  which  is  a  substance  resembling  globulin  and 
mucin.  Heat  does  not  coagulate  its  solutions.  Acetic 
acid  renders  them  turbid,  and  an  excess  of  the  acid 
re-dissolves  the  precipitate.  These  solutions  are  pre- 
cipitated by  potassium  ferrocyanide  and  nitric  acid. 

After  having  been  evaporated  to  dryness,  this  sub- 
stance no  longer  dissolve-;  in  water,  but  is  dissolved  in 
very  dilute  alkaline  solutions. 


372  ANIMAL    CHEMISTRY. 

The  fecundating  property  of  the  spermatic  fluid  rests 
iu  the  spermatozoids.  They  preserve  vitality  for  a  long 
time  in  the  urine,  and  even  in  a  dry  state.  If  a  cloth 
impregnated  with  dry  sperm  be  moistened  and  placed 
on  the  stage  of  a  microscope,  the  active  spermatozoids 
are  readily  perceived.  Spots  of  semen  heated  slightly 
for  a  few  minutes  assume  a  dark  yellow  colour. 

The  seminal  liquid  contains  in  suspension,  besides 
the  spermatozoids,  white  granular  corpuscles,  mucus, 
and  debris  of  epithelium.  It  holds  in  solution,  in 
addition  to  spermatin,  lecithin,  various  fatty  bodies, 
sodium  carbonate — which  renders  it  alkaline — sodium 
••hloride,  and  phosphates. 


MUCUS     FLUIDS  OF  THE  SEttOUS 
MEMBKANES. 

Murus  is  a  viscous,  ropy  liquid,  containing  epithelial 
cells  and  small  colourless  corpuscles,  few  in  number  in 
a  normal  state,  but  which  increase  greatly  when  the 
membranes  are  inflamed.  The  composition  of  muciis 
in  different  parts  of  the  body  presents  differences 
not  yet  determined. 

Jlii'cin  is  the  name  given  to  that  principle  of  which, 
however,  little  is  known,  imparting  to  mucus  its  ropy 
consistency.  It  is  found  in  a  number  of  the  fluids  of 
the  body.  Eichwald  has  given  a  process  by  means  of 
which  he  extracts  this  substance  from  different  liquids 
or  tissues. 


MUCUS.  373 

It  is  most  readily  extracted  from  pulmonary  expec- 
torations. 

These  are  diluted  with  water,  and  an  excess  of  acetic 
acid  added.  The  turbid  liquid  is  washed  on  a  filter  with 
dilute  acetic  acid  as  long  as  the  filtrate  gives  a  precipitate 
with  potassium  ferrocyanide.  The  solutions  are  then 
treated  with  lime  water  and  the  mucin  precipitated 
from  the  solution  by  acetic  acid.  This  body  appears  to 
be  largely  soluble  in  water ;  it  is  precipitable  by 
alcohol  and  dilute  acids,  and  soluble  in  alkalies. 

It  is  distinguished  from  albumen  in  not  coagulating 
by  heat.  It  also  furnishes  tyrosin  under  the  action  of 
dilute  sulphuric  acid. 

GK  Gaelchli  (18-78-77)  found  that  mucin  on  putre- 
fying generated  indol,  phenol,  and  a  sugar-like 
substance. 

Normal  mucus  does  not  contain  albumen. 

An  analysis  of  nasal  mucus  by  Nasse  yielded  : 

Water  933.7 

Mucin         ......     53.3 

Lactates  and  extract  soluble  in  alcohol       3.0 
Extract  soluble  in  water  and  phosphates       3.5 
Alkaline  chlorides        .         .         .         .5.6 

fSodium  hydrate  ...  .       0.9 

1000.0 


374  ANIMAL    CHEMISTRY. 

Urine  left  standing  for  a  short  time  often  deposits 
mucus  which  is  whitish,  soluble  in  the  alkalies,  and 
partially  in  acids.  It  facilitates  the  transformation  of 
the  urea  present  into  ammonium  carbonate. 

SEROSITY  effects  the  lubrication  of  various  surfaces  of 
the  body,  preventing  friction  ;  its  composition  varies 
slightly  in  different  organs.  Albumen,  mucus,  and 
soda  are  ordinarily  found  in  it. 

Synovia  'is  the  serosity  which  lubricates  the  joints. 
It  is  dense  and  slightly  alkaline.    It  differs  from  mucu 
in  containing  albumen. 

According  to  Berzelius,  it  contains : — 

Water  ....  .926 

Albumen 64 

Extractive  matters  and  soluble  salts  6 

Calcium  phosphate          .         .         .  1.5 

Its  composition,  however,  varies  according  to  amount 
of  exercise  taken. 

ANALYSIS    OF    THE    HYDROCEPHALUS    FLUID. 

Mucus  with  a  trace  of  albumen       .  0.112 

Sodium  carbonate  ....  0.124 

Sodium  chloride  0.664 

Potassium  chloride  and  sulphate  traces 

Calcium  phosphate          .         .  „ 

Magnesium  phosphate    ...  ., 

Iron  phosphate       ....  0.020 

Water  ......  99.080 

100.000 
(Marcet.) 


COLLOIDIN.  375 

ANALYSIS    OF   THE    HYDROPSICAI,    FU'ID. 

Albumen        .         .         .         .         .  2.38 

Urea 0.42 

Sodium  chloride     .         .          .         .  0.81 

Sodium  carbonate  .          .          .          .  0.21 
Sodium   phosphate,  with   traces   of 

sodium  sulphate          .         .         .  0.06 

Mucous  substance  ....  0,89 

Water  .  95.23 


100.00 
(Marchand.) 


VESICULAR   SEROSITY. 


Coagulable  albumen       .         .         .  5.25 

Albumen  more  soluble  in  water      .  0.50 

Salts 0.26 

Water 93.99 

100.00 
(Brandes  and  Hermann.) 

COLLOIDIN.  —  Gautier,  Cazeneuve,  and  Daremberg 
(97-[2]  21-482)  have  examined  the  jelly-like  contents 
of  a  large  ovarian  cyst :  they  diluted  the  same  with 
water,  heated  to  110  degrees  in  closed  vessels,  filtered 
after  allowing  to  cool,  diaiyzed  the  nitrate  in  order  to 
remove  the  salts,  and  precipitated  with  alcohol,  whereby 
they  obtained  a  white  floeculent  mass,  soluble  in  water, 


376  ANIMAL    CHEMISTRY. 

and  not  precipitated  either  by  metallic  salts  or  mineral 
acids,  but  precipitable  by  tannic  acid  and  alcohol. 
They  have  called  this  substance  colloidin,  and  give  as 
its  formula  C9H15N06.  According  to  Grorup-Besanez 
this  body  is  closely  allied  to  mucin. 


MILK. 

Milk  is  a  white,  opaque  liquid,  inodorous  while  cold, 
and  of  a  slightly  sweetish  taste. 
Its  density  varies  but  little  : — 

Human  milk 1.0320 

Cows'        „ 1.0300 

Goats'        „ 1.0341 

Asses'        „ 1.0355 

Sheep's     „      .  ...  1.0409 

Human  milk  is  alkaline.  The  milk  of  herbivora 
has  generally  the  same  reaction.  That  of  carnivora  is 
believed  to  be  acid;  at  least  it  acidities  so  quickly  when 
once  drawn  that  it  is  difficult  to  state  its  reaction 
positively. 

Milk  is  formed  of  an  almost  colourless  and  trans- 
parent liquid,  in  which  float  an  immense  number  01 
oleaginous  globules.  These  globules  are  visible 
only  under  the  microscope ;  their  size  varies  from 
0.0027  m.m.  to  0.0041  m.m.  They  are  opaque,  and  it 
is  to  these  globules  that  the  opacity  of  the  milk  is  due. 
The  fatty  bodies  of  whicli  they  are  formed  are  probably 


MILK.  377 

contained  in  an  albuminoid  membrane.  If  to  milk  we 
add  a  little  potassium  hydrate  and  ether,  the  alkali 
dissolves  the  membrane,  the  ether  absorbs  the 
fatty  bodies,  and  the  milk  is  changed  into  a  limpid, 
transparent  liquid.  On  placing  some  milk  under  a 
microscope,  and  moistening  it  with  a  drop  of  acetic 
acid,  the  membrane  will  be  seen  tD  be  attacked,  and  the 
fatty  bodies  will  immediately  run  together,  while  if  it 
be  simply  agitated  with  ether,  the  globules  re- main 
unchanged. 

Robin,  however,  supposes  that  the  milk  globules 
have  no  special  envelope,  but  are  surrounded  by  a 
thin  layer  of  a  saponaceous  matter  formed  of  fatty 
bodies,  salts,  and  albuminoid  compounds. 

Milk  left  to  itself  separates  into  two  layers;  that 
formed  above,  by  the  union  of  the  globules,  constitutes 
the  cream,  that  below  forms  a  white  liquid,  having  a 
slightly  blue  tinge. 

On  subjecting  milk  to  a  violent  and  prolonged 
beating,  the  globules  unite  and  separate  from  the 
liquid,  and  butter  is  obtained.  The  fatty  bodies  of 
milk  are  formed  of  several  principles  :— 

Butyrin,  caproin,  caprin;   about    .         .       2. 

Olein .30. 

Margarin      ......     68. 

And  a  small  amount  of  stearin. 

But  these  proportions  are  necessarily  very  variable. 
E.    Tisserand  (46- [3]    9-440)  has    summarized  the 
following  data : — 


378  ANIMAl,    OHKM1STRY. 

I.  The  separation  of  cream  occurs  the  more  promptly 
according  as  the  temperature  approaches  0°. 

II.  The  lower  the  temperature  the  larger  the  volume 
of  cream  and  the  yield  of  butter  ;  at  the  same  time  the 
butter  milk,   butter,    and  cheese,   are  all  of  a   better 
quality. 

In  human  milk  the  mean  percentage  of  butter  is 
2.42.  It  ranges  between  2.80  and  3.50  in  cows' 
milk. 

According  to  different  experimenters  the  margarin 
is  very  impure ;  it  contains  stearin,  myristin,  and  even 
other  compounds. 

The  lower  layer  contains  various  substances,  of 
which  the  principal  ones  are : — 

Casein,  an  albuminoid  matter  previously  described  : 
the  milk  contains  more  of  this  substance  after  a 
nourishment  of  nitrogenous  food  than  after  one  of 
vegetable  matters. 

Sugar  of  milk. 

Different  salts,  principally  phosphates  and  chiefly 
calcium  phosphate  ;  sulphates  are  not  present. 

Milk  allowed  to  stand  in  the  air  rapidly  loses  its 
alkaline  reaction  and  becomes  acid.  It  then  coagulates. 
This  effect  is  due  to  the  lactic  acid  which  forms  spon- 
taneously in  milk.  It  is  formed  by  a  fermentation 
called  lactic  fermentation. 

The  sugar  of  milk  is  the  substance  which  is  trans- 
formed into  lactic  acid  with  the  co-operation  of  nitro- 
genous ferments. 

The  coagulum  is  formed  of  casein  and  fatty  sub- 


MILK.  379 

stances  the1  liquid  which  remains  is  known  an  butter 
milk. 

A.  Vogel  (75-23-505)  confirms  the  observations  of 
Schwalbe  (36-1872-833)  that  oil  of  mustard  pre- 
vents the  coagulation  of  milk  ;  according  to  his  investi- 
gations the  formation  of  lactic  acid  is  in  a  great 
measure  hindered  by  the  presence  of  the  oil  of  mustard. 
Oil  of  bitter  almonds  and  oil  of  cinnamon  prevent  the 
formation  of  this  acid  to  a  less  degree,  while  oil  of 
turpentine,  oil  of  cloves,  benzol,  carbolic  acid,  carbon 
bisulphide,  and  hydrogen  sulphide  are  almost  without 
action. 

It  is  an  alkali,  soda,  which  holds  the  casein  in 
solution  in  fresh  milk,  and  milk  may  be  kept  fresh  for 
a  very  long  time  by  simply  adding  to  it  a  few 
thousandths  of  an  alkaline  bicarbonate.  On  the  other 
hand,  milk  will  at  once  coagulate  on  the  addition  of 
an  acid. 

Besides  the  acids,  a  large  number  of  substances 
possess  the  property  of  causing  milk  to  coagulate  ;  such 
are  alcohol,  tannin,  different  salts,  many  plants  which 
are  not  acid,  the  flowers  of  the  artichoke,  of  the  thistle, 
and  of  the  butter  wort  (Pingmcula  vulgaris),  which 
render  it  ropy,  and  especially  rennet,  a  substance 
obtained  from  the  stomachs  of  sucking  calves.  One 
part  of  renuet  will  coagulate  30,000  parts  of  milk,  and 
the  wooden  vessels  which  have  contained  rennet,  and 
which  are  used  in  dairies,  may  be  used  for  a  very  long 
time  for  the  operation  without  any  subsequent  addition 
of  this  substance.  According  to  certain  experimenters 


380 


ANIMAL    CHEMISTRY, 


rennet  effects  the  transformation  of  a  certain  amount  of 
the  sugar  of  milk  into  acetic  acid ;  according  to  others 
this  transformation  is  produced  by  an  albuminoid  sub- 
stance called  chymosin.  The  coagulum  of  milk  is 
employed  in  making  cheese. 

The  nature  of  the  food  influences  the  character  and 
quantity  of  this  secretion.  The  butter  increases  if  the 
food  contains  much  fatty  matter  and  when  the  food  is 
vegetable.  A  mixed  or  animal  diet  diminishes  the 
proportion  of  butter,  and  increases  the  proportion  of 
casein  and  sugar. 

Fasting  diminishes  the  secretion.  The  milk  is  then 
poor  in  sugar  and  salts,  and  becomes  rich  in  fat  and 
casein. 

During  certain  affections  of  the  mammillary  glands, 
mucus,  infusoria,  fibrin,  and  epithelial  Mbri*  are  found 
in  the  milk. 

Albumen  occurs  in  the  milk  when  the  mammillary 
glands  are  the  seat  of  inflammation.  In  B  right's 
disease  urea  passes  into  the  milk. 

COMPOSITION    OF    MILK,    BY    BQUSSINGAULT. 


Hi  mi.  -tn.      Cow. 

Ass. 

Goat. 

Mare. 

Dog. 

Water    

88.4     1    87.4 

90.5 

82.0 

89.63 

66.30 

Butter    

2.5     !      4.0 

1.4 

4.5 

traces 

14.75 

Sugar  of  milk  and  .sol- 
uble salts  
Casein,    albumen,     and 
insoluble  salts  

4.8     '      5.0 
3.8     i      3.6 

GA 
1.7 

4.5 
9.0 

8.75 
l.GO 

2.95 
16.00 

99.5     1  100.0 

100.0 

100.0 

99.98 

100.00 

COMPOSITION    OF    MILK    OF    A   WOMAN. 


381 


Mott  (100-6-364)  finds  milk  of  the  negro  race 
richer  in  solid  matter  than  that  of  the  Caucasian. 

According  to  recent  investigations  of  Lieberman 
(1-181-102)  there  is  another  albuminoid  substance 
in  milk  besides  those  given  in  the  foregoing  table,  but 
which  has  not  yet  been  isolated. 


COMPOSITION  OF  THE   MILK  OF  A  WOMAN,    AT    DIFFERENT 
PERIODS,  BY  SIMON. 


Days  after 
Child- 
birth. 

Specific 
Gravity. 

Water. 

Dry 
Res-idue. 

Casein. 

Sugar. 

Butter. 

Mineral 

Salts. 

2 

1.0320 

82.80  I    17.20 

4.00 

7.00 

5.00    ;    0.316 

10 

1.0316 

87.32  !     12.68 

2.12 

6.24 

3.46 

1.180 

17 

1.0300 

88.38 

11.62 

1.96 

5.76 

3.14 

0.166 

18 

1.0300 

89.90 

10.10 

2.57 

5.23 

1.80 

0.200 

24 

1.0300 

88.36 

11.64 

2.20 

5.20 

2.64 

0.178 

67 

1.0340 

89.32 

10.68 

4.30 

4.50 

1.40 

0.274 

74       !    1.0320 

88.60 

11.40 

4.52 

3.92 

2.74 

0.287 

82           1.0345 

91.40 

8.60 

3.55 

3.95 

0.80 

0.240 

89       i    1.0330  :    88.06 

11.94 

3.70 

4.54 

3.40 

0.250 

96 

1.0334       96.04 

10.96 

3.85 

4.75 

1.90 

0.270 

102 

1.0320   '    90.20 

9.80 

3.90 

4.90 

0.80 

0.208 

109 

1.0330       89  00 

11.10 

4.15 

4.30 

2.20 

0.276 

117 

1.0344   :    89.10 

10.90 

4.20 

4.40 

2.00 

0.268 

132 

1.0340       86.14 

13.86  i     3.10 

5.20 

5.40 

0.235 

136 

1.0320       87.36 

12.64   !     4.00 

4.00 

3.70 

0.270 

According  to  Berzelius,    skimmed  cows'  milk  con- 
tains : — 

Casein,  with  a  small  quantity  of  butter  2.600 

Sugar  of  milk  ....  3.500 

Alcoholic  extract,  lactic  acid,  lactates  0.600 

Potassium  chloride  0.170 


882  ANIMAL    CHEMISTRY. 

Alkaline  phosphate  .         .  .       0.025 

Calcium   phosphate,    lime   combined 
with  casein,  magnesia,  and  traces 
of  iron  oxide         ....       0.230 
Water  92.875 


100.000 

H.  Eitthausen  (18-77-348)  has  recently  found  in 
milk  another  carbohydrate,  differing  from  milk  sugar, 
and  more  resembling  dextrin. 

FLESH. 

We  can  have  only  imperfect  ideas  in  regard  to  the 
transformations  which  the  plastic  principles  (albumen, 
fibrin,  casein)  undergo  in  being  converted  into  assimi- 
lable matter  and  tissue,  also  as  to  the  manner  in  which 
each  organ  selects  from  the  nutritive  substances  the 
elements  which  are  suited  for  its  use. 

It  is  certain  that  albumen  plays  the  principal  role, 
for  it  is  observed  to  give  rise  to  fibrin  and  other  nitro- 
genous substances  under  certain  circumstances,  and 
especially  in  the  incubation  of  the  egg;  certain  physi- 
ologists have  also  thought  that  in  digestion  all  nitro- 
genous substances  are  converted  into  albumen,  and  that 
in  nutrition  the  albumen  is  changed  into  fibrin,  a 
substance  which,  from  the  facility  with  which  it  coagu- 
lates, is  the  principal  agent  in  the  creation  and  renewal 
of  the  tissues,  that  is,  of  the  solid  portion?  of  our 
bodies. 


MUSCULAR   TISSUE. 


388 


These  ideas  are  probably  exaggerated,  or  at  the  least 
their  correctness  has  not  been  demonstrated. 

MUSCULAR  TISSUE. — The  muscles  are  constituted  of 
a  reddish  contractile  tissue,  formed  of  fusiform  elon- 
gated cells  and  of  striated  filaments,  constituting  an 
external  envelope,  called  the  sarcolemma,  and  of  inter 
nal  substances,  from  which  a  variety  of  fibrin,  syntonin, 
may  be  extracted. 

This  latter  is  probably  the  substance  into  which 
albuminoid  matters  are  changed  during  digestion  in 
the  stomach  (parapeptone). 

Solutions  of  syntonin  in  acids  are  not  coagulated  by 
boiling ;  they  are  precipitated  by  chlorides  and  alkaline 
sulphates.  Syntonin  dissolves  in  caustic  alkaline  liquids 
and  in  dilute  solutions  of  carbonates,  and  is  repre1  ipi- 
tated  when  these  solutions  are  neutralized,  even  in  the 
presence  of  alkaline  phosphates.  This  last  character 
distinguishes  it  from  the  albuminates. 

The  fibres  of  the  muscles  are  surrounded  by  a  fluid 
which  may  be  considered  as  the  plasma  of  the  muscles. 
It  may  be  prepared  according  to  Kiihne  by  removing 
the  muscles  of  an  animal  recently  killed,  and  freezing 
them  at  a  temperature  of  about  —  7°,  whereby  they 
become  v^ry  brittle.  They  are  pulverized  in  a  well- 
cooled  mortar,  and  thereupon  subjected  to  a  heavy 
pressure  in  an  appropriate  press.  A.  liquid  is  thus 
obtained,  which  is  placed  upon  a  filter  surrounded  by 
a  refrigerating  mixture.  The  liquid,  which  filters 
very  slowly,  is  opaline-yellowish,  viscid,  and  alkaline. 
It  coagulates  at  ordinary  temperatures,  furnishing 


384 


ANIMAL    CHEMISTRY. 


myosin,  which  may  be  readily  obtained  by  causing  the 
filtrate  to  fall  into  water  at  the  ordinary  temperature. 
If  acid  solutions  of  myosin  are  saturated,  it  is  then  no 
longer  this  body  which  precipitates  but  syntonin.  Syn- 
tonin  differs  from  myosin  by  not  dissolving  in  solutions 
containing  less  than  10  to  12  per  cent,  of  common  salt. 
Myosin  may  also  be  obtained  more  simply  by  pounding 
flesh  with  water  containing  8  to  9  per  cent,  of  common 
salt.  After  allowing  this  to  stand  twenty-four  hours 
it  is  filtered  by  being  pressed  through  cloth,  and  the 
myosin  precipitates  on  pouring  the  liquid  into  water. 

The  liquid  which  remains  after  the  coagulation  of 
myosin  contains,  according  to  Kuhne,  two  albuminoid 
substances,  one  coagulable  at  75°,  the  other  at  45°,  and 
alkaline  albuminates ;  also  salts,  which  are  chiefly 
phosphates,  lactic  acid,  and  lactates ;  sugar  and  various 
organic  substances,  as  creatiu,  creatinin,  inosic  acid, 
inosite,  sarcosin,  sarkin,  and  xanthin.  This  liquid  is 
coagulable  by  heat,  and  of  a  red  colour ;  its  acidity  is 
due  to  lactic  acid  and  acid  phosphate  of  potassium, 
which  may  be  extracted  from  the  muscles  by  dilute 
alcohol. 

It  is  claimed  by  Fremy  and  others  that  there  exists 
in  the  muscles  a  special  acid,  called  oleophosphoric  acid, 
and  that  this  acid  is  combined  with  sodium. 

According  to  Dubois  Eeymond,  the  muscles  do  not 
possess  an  acid  reaction  until  after  death,  and  while 
contractile  th<nr  reaction  is  slightly  alkaline. 

In  certain  pathological  states,  urea,  uric  acid,  and 
various  other  products  are  present. 


COMPOSITION    OF    FLESH.  385 

H.  Struve  (60-'76-623)  finds  in  fatty  muscular  tissue 
a  new  body  which  gives  the  absorption  spectra  of  blood, 
but  is  changed,  unlike  the  latter,  by  the  action  of 
alkaline  sulphides  and  acids. 

COMPOSITION    OF    FLESH. 

Pectoral  Muscles. 

Man.  Woman. 

Water        ....  72.46  74.45 
Muscular  fibres,  vessels,  and 

nerves    ....  16.83  15.54 

Fats 4.24  2.30 

Extractive  matters      .        .  2.80  3.71 

Cellular  tissue    .         .         .  1.92  2.07 

Soluble  albumen          .         .  175  1.93 

100.00       100.00 
(Von  Bibra.) 

Flesh  leaves  from  2  to  8  per  cent,  of  ash,  formed 
chiefly  of  alkaline  and  earthy  phosphates ;  sodium 
chloride  and  sodium  sulphate  are  also  present, 

The  brcth  produced  by  digesting  muscular  tissue  in 
water  contains,  according  to  Chevreul : — 

Water        ...  .  988.57 

Organic  substances  dried  in  a  vacuum     12.70 
Salts  (phosphates,  sulphates  and  chlo- 
rides of  potassium,  sodium,  calcium, 
magnesium,  and  iron)     .         .         .       3.23 

1004.50 


386  ANIMAL    CHEMISTRY. 


CREATIN,  C4H9N3O2 
OREATININ,  C4H7N3O. 
SARCOSIN,  C3H7NO2. 

These  three  bodies  have   the  highest  importance  in 
connection  with  the  study  of  muscular  tissue. 
Liebig  found  in  : 

Muscular  flesh  of  the  ox          .     0.69    creatin. 
„  „         „      horse     .     0.72         „ 

Creatin  is  prepared  by  treating  meat  cut  into  very 
small  pieces  with  cold  water  as  long  as  anything  is 
dissolved,  and  the  solution  evaporated;  the  concentrated 
liquid,  filtered,  furnishes  creatin. 

This  body  occurs  in  rectangular  prisms,  without 
taste  or  odour,  soluble  in  74  parts  of  cold  water,  but 
more  soluble  in  boiling  water. 

On  being  boiled  with  strong  acids  it  furnishes  creatinin. 

HC1  +  C4H9N302=H20  +  C4H7X,0,HC1 

Chlorhydrate  of  creatinin. 

This  chlorhydrate  decomposed  furnishes  creatinin  as 
a  crystalline  alkaline  substance,  more  soluble  than 
creatin  in  both  water  and  alcohol.  Creatinin  may 
be  reconverted  into  creatin  by  boiling  with  lead  oxide. 

It  forms  with  zinc  chloride  a  combination  which  is 
but  slightly  soluble  in  cold  water.  According  to 
Neubauer,  creatin  does  not  exist,  in  flesh,  but  creatinin 
only,  and  the  creatin  which  is  found  is  formed  by  the 
transformation  of  the  creatiuin.  Creatinin  also  exists 
in  urine,  and  in  the  muscles  of  the  Crustacea. 


,.,      XANTHIN...  .  3$7 

•  '  * 

On  submitting  creatinin  to  a  prolonged  .ebullition 
with  baryta  water  another  substance  is  formed,,  called 
sarcosin. 

H20  +  C4H9N302=CR4N20  +  03H7NO2 ' "' '" 

Urea.  Sarcosin.       ,  ;  . . 

This  body  crystallizes  in  rhombic  crystals,  which  are 
colourless,  very  soluble  in  water,  somewhat  soluble  in 
alcohol  and  insoluble  in  ether.  Sarcosin  melts  at  a 
temperature  above  100°,  and  is  volatile.  It  possesses 
the  characters  of  glycocol  and  its  homologous  sub- 
stances. 

INOSIC  ACID. — The  mother  liquor  of  creatin  is  acid, 
and  has  an  odour  of  meat  broth.  Extract  of  meat 
treated  with  baryta  furnishes  on  evaporation  inosate  of 
barium,  and  the  liquid  contains  inosite.  The  formula 
of  inosic  acid  is  usually  given  as  C5H8N"206,  though 
some  authors  regard  it  as  C10H14N4On  (21  ~2 69). 

XANTHIN. — C5H4N402.  To  prepare  this  substance 
muscular  tissue  is  well  beaten,  and  alcohol  and  water 
successively  added  as  long  as  anything  is  dissolved. 
These  two  liquids  are  now  united  and  heated,  in  order 
to  coagulate  the  albumen  and  drive  off'  the  alcohol. 
The  liquid  is  filtered,  and  lead  subacetate  added.  The 
precipitate  is  collected,  washed,  and  decomposed  with 
hydrogen  sulphide  while  suspended  in  water.  The 
filtered  liquid  is  boiled  and  evaporated.  The  xanthin 
deposits  in  a  non-crystalline  mass.  It  can  also  be 
prepared  from  the  liver.  Xauthin  is  soluble  in  cold 


S88  ANIMAL    CHEMISTRY. 

water,  alcohol,  and  ether.  It  forms  with  acids  salts 
which  are  generally  orystalliaable  ;  it  is  precipitated 
even  from  very  dilute  solutions  by  mercuric  chloride  or 
nitrate. 

It  dissolves  in  alkaline  liquids.  If  calcium  hypo- 
ohlorite  he  added  to  one  of  these  solutions,  a  greenish 
precipitate  is  formed  which  becomes  brown  and  then 
disappears.  This  reaction  is  quite  delicate,  and  a 
useful  test. 

OTHER  TISSUES. 

CELLS. — The  cells  are  the  simplest  structures  of  the 
body.  Their  mass  is  very  minute,  and  their  form 
variable.  They  are  not  always  enclosed  by  an  envelope, 
and  they  vary  in  their  chemical  nature.  They  contain 
one  or  more  nuclei,  and  when  new  a  gelatinous  liquid 
(protoplasm),  capable  of  contractile  movements  under 
the  influence  of  chemical  agents,  of  electrical  or 
mechanical  forces.  If  old,  they  contain  different 
matters,  derived  either  from  modifications  of  the  proto- 
plasm <>r  the  introduction  of  foreign  substances. 

The  protoplasm  coagulates  after  death.  It  appearp 
to  contain  rnyosin,  also  other  albuminoid,  fatty,  and 
saline  constituents. 

AREOLAR  TISSUE  is  chemically  characterized  by  the 
action  which  hot  water  has  upon  it. 

At  first  it  swells,  assumes  a  jelly-like  appearance, 
and  fiually  dissolves,  producing  gelatin,  which,  on 
cooling,  is  of  a  tremulous  consistency. 


Dilute  inorganic  acids  and  dilute  alkalies  also  effect 
this  transformation.  There  is  believed  to  exist  in  this 
tissue  a  substance  (collagene,  glutine,  geline)  analogous 
with  ossein,  which,  in  contact  with  hot  water,  furnishes 
gelatin ;  also  a  substance  (elastin)  not  furnishing 
gelatin. 

Tannin  and  mercury  dichloride  form  with  these 
matters  imputrescible  compounds. 

Cellular  tissue  is  converted  into  a  transparent  and 
colourless  jelly  by  the  action  of  strong  acetic  acid ;  but 
the  fibre  is  not  attacked,  for  if  the  acid  be  saturated 
with  ammonia  water  it  reappears  in  its  ordinary 
condition. 

The  elastic  tissue*  do  not  dissolve  even  after  an  ebulli- 
tion of  sixty  hours,  and  do  not  furnish  gelatin. 

Hydrochloric  acid  dissolves  them,  turning  brown  at 
the  same  time.  With  sulphuric  acid  they  furnish 
leucin  and  not  gelatin.  This  may  be  obtained  quite 
pure  by  boiling  cellular  tissue  with  water,  then  with 
acetic  acid,  and  macerating  the  residue  with  a  dilute 
alkaline  solution.  To  the  product  thus  obtained  the 
name  of  elastin  has  been  given. 

The  mucous  areolar  tissue  differs  chemically  from 
ordinary  conjunctive  tissue,  in  that  it  does  not  furnish 
gelatin  on  being  boiled  with  water. 

The  reticular  tissue  of  the  cutis  contains  the  pig- 
ment called  in  damn,  the  colouring  matter  of  the  skin. 
This  tissue  is  not  reproduced  completely  where  destroyed, 
but  is  replaced  by  cellular  tissue,  and  the  cicatrix  is 
due  to  the  fact  that  this  latter  tissue  is  colourless. 


390  ANIMAL   CHEMISTRY. 

The  epidermis  furnishes  gelatin  on  boiling  with  water. 

It  appears  to  contain  iron,  and  H.  P.  Floyd 
(84-34-179)  has  found  it  to  "contain  in  the  negro 
twice  as  much  of  this  element  as  in  whites. 

Sulphuric  acid  softens  and  dissolves  it,  nitric 'acid 
colours  it  yellow,  alkalies  dissolve  it,  the  sulphides 
render  it  of  a  brown  colour,  and  silver  salts  blacken  it. 

The  epidermis,  hair,  bristles,  feathers,  nails,  horns, 
and  epithelium  have  an  almost  identical  composition. 


Epi- 

Epi- 

Hair and 

dermis. 

thelium. 

Bristles. 

Nails. 

Feathers. 

Horn. 

Carbon 

50.34 

51.53 

50.00 

51.00 

52.42 

50.94 

Hydrogen    . 

6.81 

7.03 

6.40 

6.82 

7.21 

6.65 

Xitrogeii 

17.22 

16.64 

17.00 

17.00 

17.89 

16.28 

O-xyg'en  arid 

sulphur     . 

25.63 

24.80 

26.60 

25.18 

22.48 

26.13 

100.00  100.00  100.00  100.00  100.00  100.00 

The  horny  tissues  are  formed  of  cells  containing 
nuclei  which  have  united  and  dried.  Indeed,  when 
these  different  tissues  are  treated  with  alkaline  solu- 
tions, ovoid  cells  are  seen,  each  containing  a  nucleus. 
Sulphuric  aoid  likewise  renders  this  structure  apparent. 
This  tissue  leaves  about  1  to  1.0  per  cent,  of  ash  on 
ignition. 

Horn  treated  with  fused  potassium  hydrate  and  with 
dilute  sulphuric  acid,  furnishes  tyrosin  and  leuoiu. 

Hydrochloric  acid  renders  it  blue,  nitric  acid  yellow  ; 
aqua  regia  attacks  it  with  energy. 

-Feathers  possess  the  same  general  properties.  The 
colour  of  the  feathers  is  due  to  different  pigments, 
rarely  soluble  in  water,  sometimes  in  ammonia,  and 


CARTILAGINOUS   TISSUE.  391 

ordinarily  ill  alcohol.  They  generally  contain  less 
oxygen  and  more  silica  than  horn  and  analogous 
tissues. 

Hair  has  the  same  composition  and  chemical  char- 
acters as  horny  tissue. 

Its  colour  is  due  to  oils  of  various  tints.  With  age 
this  oily  secretion  ceases  to  he  produced  and  the  hair 
whitens  ;  the  white  colour  seeming  to  be  due  to  the  fact 
that  the  tubes  contain  no  secretion,  but  are  filled  with 
air.  The  fatty  bodies  of  the  hair  are  formed  from  the 
volatile  acids  of  perspiration,  and  also  of  margarin, 
olein,  and  stearic  acid.  Hodgkinson  and  Sorby  ob- 
tained (28-222-592)  from  black  hair  and  feathers  a 
black  pigment,  to  which  they  ascribe  the  formula 
C18H1?N808.  _ 

Hair  contains  0.5  to  2.0  per  cent,  of  inorganic  sub- 
stances, containing  a  considerable  proportion  of  iron 
and  small  quantities  of  silica.  Mulder  found  in  epi- 
dermis an  organic  sulphur  compound  he  called  keratin. 
CARTILAGINOUS  TISSUE. — The  cartilages  are  ordi- 
narily formed  of  a  flexible  tissue,  whose  composition  is 
not  greatly  different  as  to  its  organic  constituents  from 
that  of  the  preceding  substances,  tbough  varying  in 
organic  composition  with  age  and  in  the  different  parts 
of  the  body  : — 

Carbon        .          .  .     50.91 

Oxygen       .....        6.96 
Nitrogen    .  .          .      14.90 

Oxygen      .  .         .     27.23 

100.00 


392  ANIMAL   CHEMISTRY. 

Hoppe-Seyler  found  in  a  proximate  analysis  of 
cartilage  from  the  knee  of  a  man  aged  twenty-two 
years: — 

H20 75.59 

Organic  matter  ....     24.87 
Inorganic  matter         .         .         .       1.54 

100.00 

This  tissue  is  not  homogeneous ;  under  the  micro- 
scope it  appears  composed  of  a  colourless  fibre  and  cells 
containing  granulated  protoplasm.  The  matter  of  the 
cells  is  different  from  the  gelatinous  substance  forming 
their  envelopes.  It  does  not  dissolve  in  boiling  water 
even  under  pressure. 

The  cartilaginous  substance  proper,  cartilagein,  fur- 
nishes, with  boiling  water,  a  substance  which  resembles 
gelatin  in  its  composition,  but  from  which  it  differs  in 
several  characteristics,  and  especially  by  its  giving  a 
precipitate  with  acids,  lead  acetate,  and  alum,  while 
gelatin  gives  no  reaction  with  these  substances.  It  is 
called  by  the  name  of  choi<drin.  Chondrin  turns  the 
plaue  of  polarization  to  the  left.  Treated  with  hydro- 
chloric acid  it  furnishes  a  variety  of  glucose  (chondro- 
ylucoxe)  and  various  nitrogenous  substances  of  which 
little  is  known. 

A  distinction  has  lately  been  made  between  the 
cartilages  just  spoken  of  and  the  fibro-cartilages.  These 
last  contain  a  fibrous  matter  without  nuclei,  differing 


KBKVB   TISSUE.  893 


from  the  ordinary  cartilaginous  substance  by  producing 
with  boiling  water  a  substance  which  is  but  slightly 
precipitated  by  tannin.  The  fibre-cartilage  of  the  knee 
must  also  be  distinguished  from  the  preceding,  from 
the  fact  that  it  produces  gelatin  with  boiling  water. 

Cartilaginous  tissue  contains  55  to  75  per  cent,  of 
water,  2  to  5  per  cent,  of  fatty  bodies,  and  1.5  to  6 
per  cent,  of  mineral  substances. 

NERVE  TISSUE.  —  Of  it  are  composed  the  nerves, 
ganglia,  brain,  and  the  spinal  cord.  It  is  observed  to 
contain  cells  and  cylindrical  tubes  ;  these  are  formed 
of  an  envelope  of  areolar  and  fibrous  tissue  and  of  a 
semi-liquid  medullary  substance  (myelin  of  Virchow), 
which  refracts  light  strongly,  and  is  sometimes  observed 
to  flow  out  when  a  nerve  is  cut.  These  tubes  are 
united  in  bundles  which  are  enveloped  in  a  colour- 
less, lustrous,  and  fibrous  membrane  sometimes  called 
tteurilemma. 

This  membrane  may  be  rendered  apparent  by  treat- 
ing nervous  tissue  with  a  cold  dilute  solution  of  caustic 
potassa,  which  dissolves  the  nervous  substance  with  the 
exception  of  the  neurilemma.  This  membrane  is  dis- 
solved, on  the  contrary,  by  hydrochloric  acid  and 
strong  sulphuric  acid  ;  it  is  not  coloured  yellow  by 
nitric  acids. 

The  ganglions  of  the  nervous  centres  are  formed  of 
cells  of  variable  size,  composed  of  a  very  thin  envelope 
and  a  nucleus  containing  a  dense  liquid,  in  which  are 
granules  in  suspension. 

concentrated  alkaline  solutions  attack  and  dissolve 


394  ANIMAL    CHEMISTRY. 

the  nerve  cells  and  tubes.  Strong  inorganic  acids 
shorten  and  thicken  the  fibres.  An  aqueous  solution 
of  iodine  colours  them  bright  yellow.  A  mixture  of 
mercurous  and  mercuric  nitrates  renders  them  rigid 
and  tenacious. 

The  reaction  of  the  nerves  appears  to  be  neutral 
during  life,  it  becomes  acid  after  death,  and  finally,  at 
the  moment  when  putrefaction  sets  in,  it  has  an 
alkaline  reaction. 

Different  investigations  made  recently  on  the  matter 
of  the  nerves  and  brain  have  shown  that  we  are 
far  from  completely  understanding  its  compositions  ; 
Liebrich's  proiagon  is  now  regarded  as  a  mixture 
of  W.  Muller's  cerebrin  and  lecithin,  and  the  same 
may  be  said  of  Kohler's  myeloidin  and  myeloidinic 
acid. 

THE  CONSTITUENTS  OF  THE  BRAIN,  more  or  less 
constant  and  normal,  thus  far  determined  with  apparent 
certainty  are: — Wafer, — albuminoid  bodies  resembling 
myosin,  —  elast/u  (?)  —  neurokeratin,  —  miclein-,  —  collagen , 
— soluble  albumen,  coagulating  at  75°,  —  cerebrhi  and 
lecithin, — glycerinphosphoric  acid, — -fats  (?), — cholestcrin, 
inosit, — hypoxanthin,  xantliin,  kreatin, — lactatex, — vola- 
tile faff i/  acids  and  -uric  acid.  Inorganic  substance*  : 
calcium,  potassium  and  magnesium  phosphates,  iron 
oxide,  silica,  alkaline  xulnhatcx,  sodium  chloride*  and 
fluorine.  (Horsford.) 

Although  very  extended  and  repeated  investigations 
of  the  chemical  nature  of  the  brain  have  been  made, 


CONSTITUENTS  OK  THE  BRAIN.  395 

it  yet  remains,  chemically,  one  of  the  most  incompletely- 
known  animal  organs. 

It  was  W.  Mliller  who  first  obtained  the  nitrogenous 
neutral  body  from  the  brain  called  cerebrin.  It  is 
extracted  on  coagulating  by  heat  an  aqueous  extract  of 
the  cerebral  substance  ;  this  coagulum  is  separated  and 
washed  with  water,  and  treated  while  boiling  with  a 
mixture  of  alcohol  and  ether,  and  filtered  hot,  White 
flakes  separate  out  of  the  solution,  which  contains 
cholesterin,  lecithin,  and  cerebrin.  This  matter  is  the 
cerebric  acid  of  Frem.  Cerebrin  has  the  formula 


It  is  dissolved  by  sulphuric  acid,  the  solution  being 
of  a  purple  colour.  It  is  rendered  resinous  by  hydro- 
chloric acid,  and  is  transformed  by  boiling  nitric  acid 
into  an  oil  which  solidifies  on  cooling.  Gobley  claims 
to  have  also  found  cerebrin  in  the  yolk  of  eggs. 

E.  Bourgoin  (60-[2]  21-482)  purifies  cerebrin  from 
the  phosphorous  compound  which  ordinarily  adheres  to 
it  by  treating  the  same  with  a  sufficient  quantity  of 
strong  alcohol,  and  gradually  warming  ;  the  cerebrin 
dissolves  before  the  alcohol  begins  to  boil,  and  the 
phosphorous  compound  deposits  itself  on  the  bottom  of 
the  vessel  ;  the  cerebrin  separates  out  of  the  decanted 
solution  on  cooling.  The  cerebrin  should  be  again 
subjected  to  a  similar  treatment.  Bourgoin  regards  the 
protagon  of  Liebreich  (36-1865-647)  as  a  mixture  .of 
cerebrin  with  this  phosphorous  compound. 

Pure  cerebrin  shows  the  following  composition  :  —  • 


ANIMAL   CUBMISl'RY. 

Carbon      .  ..     66.35 

Hydrogen .  .     10.96 

Nitrogen   .  .        .       2.29 

Oxygen     .  ...     20.40 

Lecithin,  though  a  constituent  of  the  brain,  is  best 
obtained  from  the  yolk  of  eggs.  It  is  an  imperfectly 
crystallizable  body,  easily  fusible,  with  a  waxy  lustre, 
soluble  in  ether  and  alcohol,  and  in  general  very  easily 
decomposed.  There  appear  to  be  various  lecithines 
with  different  radicles ;  one  of  the  most  common 
appears  to  have  the  radicle  of  stearic  acid,  its  empirical 
formula  being  C^HgoNPOg.  (Thudicum.) 

The  mineral  salts  constitute  about  5  per  cent,  by 
weight  of  the  brain  in  a  dry  state.  When  the  brain  is 
in  full  action  the  elimination  of  phosphorus  appears  to 
be  greater  than  when  it  is  in  repose,  since  the  quantity 
of  alkaline  phosphates  in  the  urine  increases. 

The  composition  of  the  spinal  cord,  of  the  medulla 
oblongata,  of  the  nervous  fibres  and  ganglions  is  very 
similar  to  that  of  the  cerebral  substance.  The  medulla 
oblongata  contains  the  largest  proportion  of  fatty 
bodies. 

OSSEOUS  TISSUE. — The  bones  are  formed  of  solid 
mineral  matter  (about  70  per  cent.),  and  of  an  organic 
cartilaginous  tissue,  in  which  is  found  a  principle  called 
osseiiiy  furnishing  gelatin  with  boiling  water.  The 
bony  structure  is  pierced  with  numerous  cavities. 
Many  are  visible  to  the  naked  eye ;  others  are  extremely 
minute  canals,  which  penetrate  in  all  directions,  forming 
a  complete  network,  which  admits  of  communication 


CONSTITUENTS   OF    BONE.  397 

between  the  most  remote  points  of  the  structure  ;  these 
canals  are  concerned  in  the  nutrition  of  the  tissue. 

The  medullary  cavity  and  the  cells  of  spongy  bones 
have  a  membranous  cellular  tissue  and  blood-vessels. 

The  canaliculi  contain  only  nerves  and  blood- 
vessels. 

Marrow  is  formed,  according  to  Berzelius,  of — 

Fat 96 

Blood-vessels,  membrane         ...       1 
Extractive  substances  3 


100 

According  to  Eylerch,  the  fatty  matter  of  marrow  is 
constituted  of  three  ethers  of  glycerin,  whose  acids  are 
the  palmitic,  medullic,  and  elaidic. 
The  first  is  the  most  abundant. 

Bones   deprived   of  their   fat    and   periosteum,  are, 
according  to  Berzelius,  composed  of — 

Man. 
Calcium  phosphate  (tribasic)   53.04 

*.  Calcium  carbonate  11.30 

M-ineral  portion 

Magnesium  phosphate  .  1.16 

Sodium  chloride  and  carbonate   1 .20 

n~  _-•        ( Cartilage  (ossein)  32.17 

Organic  portion      ^ 

\  Blood-vessels         .         .  1.13 


100.00 

Ossein  has,  as  a  special  characteristic,  the  property  of 
being  transformed  by  the  action  of  boiling  water  into 

M 


398  ANIMAL    CHEMISTRY. 

gelatin.  The  membrane  which  covers  the  walls  of  the 
osseous  canals  is  formed  of  an  albuminoid  substance 
insoluble  in  boiling  water.  Nitrogenous  bodies  derived 
from  the  blood-vessels  and  nerves  are  also  found  in  the 
bones,  as  well  as  fatty  matters. 

On  treating  bones  with  a  dilute  alkaline  solution 
the  ossein  is  dissolved,  and  the  mineral  portion  remains, 
retaining  its  original  shape. 

The  composition  of  bone  does  not  vary  greatly  with 
age,  except  that  the  hard  and  compact  portion  of  the 
bones  diminishes  in  aged  people,  and  is  replaced  by  a 
spongy  and  more  brittle  material ;  also  in  children  it 
contains  more  water,  and  is  more  elastic.  It  has  been 
observed  that  in  lower  animals  the  proportion  of  calcium 
carbonate  increases  with  age. 

The  composition  of  the  bones  of  different  species  of 
animals  differs  but  little  ;  yet  the  bones  of  birds  and 
herbivorous  mammalia  are  richer  in  calcium  salts  than 
the  bones  of  carnivora  and  reptiles. 

The  bones  of  the  limbs  contain  more  inorganic 
mineral  matter  than  those  of  the  trunk ;  the  humerus 
and  femur  contain  more  than  the  other  long  bones; 
these  also  contain  less  fatty  matters  than  the  short 
bones :  the  flat  bones  contain  the  largest  proportion  of 
water. 

According  to  Fremy,  the  bones  are  not  formed  by  an 
incrustation  of  the  mineral  portion  in  the  cartilaginous 
tissue,  as  is  generally  believed,  but  by  a  juxtaposition 
of  osseous  matter,  particle  by  particle  ;  for  the  rudimen- 
tary parts  of  the  bones  of  the  foetus  have  the  same 


GELATIN,  399 

composition  as  the  bones  of  full-grown  persons,  and  the 
composition  of  the  bones  does  not  essentially  vary  with 
age. 

0.  Aeby  (18-[2]  10-408)  also  is  of  the  opinion 
that  the  cartilage  and  calcium  phosphate  of  the 
bones  are  not  combined,  and  that  the  organic  foun- 
dation of  the  bones  simply  induces  ossification  with- 
out entering  into  chemical  relations  with  the  calcium 
phosphate. 

Bones  are  used  in  the  arts  for  the  manufacture  of 
animal  charcoal  or  bone  black,  phosphorus,  and 
gelatin.  Grease  is  likewise  extracted  from  them. 
They  also  serve  as  material  for  a  great  variety  of  useful 
and  fancy  articles. 

<  TEL  ATI  N. — The  organic  portion  of  bones  is  separated 
from  the  mineral  portions  on  treatment  with  dilute 
hydrogen  chloride.  The  salts  are  thereby  dissolved ; 
this  organic  substance  alone  remains,  and,  while  retain- 
ing the  form  of  the  bone,  is  flexible,  yellowish,  and 
translucent.  This  substance,  formed  almost  exclusively 
of  ossein,  becomes  hard  on  drying,  and  again  pliable 
and  elastic  when  placed  in  water  for  a  short  time. 
Submitted  to  the  action  of  boiling  water,  it  is  trans- 
formed into  gelatin.  In  making  gelatin  bones  are  first 
treated  with  boiling  water.  The  grease  is  thereby 
separated  out  and  removed.  The  bones  are  then  placed 
in  a  digester  with  water,  and  submitted  to  a  pressure 
of  several  atmospheres  ;  the  gelatin  is  almost  completely 
dissolved,  and  t^e  mineral  portion  remains  insoluble. 
These  degelatinized  bones  form  an  excellent  manure. 


400  ANIMAL   CHEMISTRY. 

The  transformation  of  ossein  is  more  rapid -with  the 
bones  of  a  young  animal  than  those  of  an  adult. 

The  ossein  is  not  combined  with  the  calcium,  as 
can  be  very  easily  proven,  for,  if  a  few  grammes  of  bones 
and  a  quantity  of  ossein  equal  in  weight  to  that  which 
exists  in  these  bones  be  treated  with  boiling  water  the 
transformation  is  as  rapid  in  one  case  as  in  the  other, 
during  the  first  part  of  the  process. 

The  proportion  of  gelatin  produced  by  the  bone  then 
diminishes  ;  but  this  is  due  to  the  fact  that  the  calcium 
salts  of  the  exterior  layers  protect  the  interior  portions 
from  the  action  of  the  boiling  water  ;  but  if  the  surface 
of  the  bone  be  scraped  the  action  of  the  boiling  water 
again  commences. 

Pure  gelatin,  C6H10N202  (?).  when  dry  is  colourless, 
or  very  slightly  yellow  ;  elastic  and  insoluble  in  alcohol 
and  ether.  It  swells  in  cold  water,  and  dissolves  in 
boiling  water.  It  turns  the  plane  of  polarization  to  the  * 
left.  The  solution,  on  cooling,  changes  into  a  gela- 
tinous mass,  provided  it  has  not  been  boiled  too  long 
with  water.  One  per  cent,  of  gelatin  is  sufficient  to 
form  a  jelly ;  and  sulphuric  acid  converts  it  into  gly- 
oocol.  It  forms  with  tannin  an  insoluble  and  impu- 
trescible  compound,  and  this  chemical  action  is  the 
basis  of  the  art  of  tanning.  C.  Voit  (11-8-2971 
has  shown  that  gelatin  is  capable  of  partially  replacing 
albumen  and  fat,  as  a  food. 

Pathological  States. — In  arthritis,  or  gout,  the  arti- 
culations become  encrusted  with  concretions,  called 
arthriti"  calculi. 


EXOSTOSIS       CARIES.  401 


ARTHRITIC   CONCRETIONS. 

Water         ......  10.3 

Animal  matter    .         .         .                  .  19.o 

Uric  acid    .         ,         .         .                  .  20.0 
Sodium  hydrate  ...                  ,20.0 

Lime .  10.0 

Potassium  chloride       ....  2.2 

Sodium  chloride  18.0 


100.0 

(Sebastian). 

Exostosis  is  an  affection  in  which  osseous  tumours  are 
developed  on  the  bone.  An  analysis  gave  : — 

Exostosifi.         The  bone  in 
the  vicinity. 

Organic  substance  .  .     46  0  41-6 

Calcium  phosphate  ,30.0  41.6 

„       carbonate  .14.0  8.2 

Soluble  salts  .         .              10.0  8.6 

100.0  100.0 

In  caries  of  bone  the  inorganic  portion  of  the  bone 
is  destroyed,  while  the  organic  portion  remains  almost 
intact.  We  owe  to  Von  Bibra  the  following  analyses 
of  cases  of  caries  : — 


402  ANIMAL   CHEMISTRY. 

Portion  of  the 
Tibia  taken        Astragalus 
Tibia  at  the     6  centimetres    taken  from  the 

point  fr°m  the  centre  of 

amputated.  joint.  the  caries. 

Inorganic  substances     61.80         42.10         18.54 
Organic  „  38.20         57.90         81.46 

100.0(1       100.00      100.00 

In  rachitis  the  mineral  portion  is  removed  to  such  an 
extent  that  the  bones  become  incapable  of  supporting 
the  body.  The  ossein  is  also  changed,  since  boiling 
water  no  longer  furnishes  gelatin  with  these  bones. 

Bones  of  a  rachitic  child,  analyzed  by  Marchand, 
contained  : — 


Vertebral. 

Femur. 

Radius. 

Sternum. 

Cartilages 

75.22 

72.20 

71.25 

61.20 

Fat 

6.12 

7.20 

7.50 

9.34 

Calcium  phos- 

phates 

12.56 

14.78 

15.11 

21.35 

Magnesium 

phosphates  . 

0.92 

0.80 

0.78 

0.72 

Calcium     car- 

bonate 

3.20 

3.00 

3.15 

3.70 

Calcium     sul- 

\ 

phate  . 
Sodium      sul- 

(• 0.98 

1.02 

1.00 

1.68 

phate 

) 

Sodium    chlo- 

ride, calcium 

fluoride, 

iron,  etc. 

1.00 

1.00 

1.20 

2.01 

100.00 

100.00 

100.00 

100.00 

DENTAL   TISSUES.  403 

Osseous  tissues  gradually  decompose  after  death.  In 
time  nothing  remains  but  the  mineral  portions,  yet 
this  action  is  very  slow,  as  organic  matter  has  been 
found  in  bones  buried  for  several  centuries.  The 
character  of  the  soil  or  other  medium  in  which  bones 
are  placed  has  a  great  influence  upon  the  rapidity  of 
this  change. 

The  ossein  which  has  not  yet  been  wholly  decom- 
posed has  the  same  characters  as  ossein  from  fresh 
bones;  it  is  capable  of  furnishing  gelatin. 

DENTAL  TISSUES. — Three  substr.v.ces  are  distin- 
guished in  the  teeth :  the  dentine,  which  forms  the 
greater  part  of  the  teeth ;  the  cement,  which  covers  the 
cervix  and  roots ;  and  the  enamel. 

The  cement  has  a  structure,  similar  to  that  of  the 
bones.  It  has  a  cavity  which  contains  the  nerves  and 
blood-vessels,  and  in  which  arise  the  little  canals  which 
ramify  and  penetrate  to  the  surface  of  the  teeth. 
Treated  with  an  acid,  it  parts  with  its  inorganic  con- 
stituents, and  there  remains  an  organic  residue  capable 
of  furnishing  gelatin,  according  to  some  authors,  though 
denied  by  Hoppe-Seyler.  The  cement  has  the  com- 
position, substantially,  of  the  bones. 

The  enamel  is  hard  and  brittle ;  it  contains  about 
90.  per  cent,  of  calcium  phosphate,  and  a  considerable 
quanity  of  calcium  fluoride,  and  only  2  to  6  per  cent, 
of  organic  substances.  When  treated  with  dilute 
hydrogen  chloride,  the  calcium  phosphate  dissolves, 
and  prismatic  fibres  remain,  which  are  not  attacked  by 
boiling  water,  and  comport  themselves  like  epithelium. 


404  ANIMAL   CHEMISTRY. 

Berzelius  found  in  the  teeth  : — 

Organic  matter   .....     28.0 

Calcium  phosphate       .         .         .  .64.4 

Magnesium  phosphate.         .         .  .       1.0 

Calcium  carbonate        .         .         .  .5.3 

Sodium          „         and  chloride    .  .       1.3 

Water,  animaJ  matter,  alkali  (traces)  .       0.0 


100.0 

The   inorganic  portion,   according   to   Fre"my,  con- 
sists of: — 

t.  r  Calcium     Magnesium  Calcium 

Phosphate.  Phosphate.  Carbonate 

Dentine      .     76.8  70.3  4.3  2.2 

Cement       .     67.1  60.7  1.2  2.9 

Enamel       .     96.9  90.5         traces          2.2 

Minute  amounts  of  chlorine  and  fluorine  exist  especially 
in  the  enamel. 

The  following  are  more  recent  analyses  by  Aeby  : — 

Cement.  Dentine. 

Calcium  phosphate .  .     61.32  93.35 

oxide          .  .       5.27  0.86 

,.        carbonate  ,  .       1.61  4.80 

sulphate     .  .       0.09  0.12 

Magnesium  carbonate  .       0.75  0.78 

Ferric  oxide     .  .0.10  0.09 

Organic  substances  .  .     27.70  3.60 


CHEMISTRY    OF    THE    EYE.  -105 

Molar  teeth  appear  to  contain  more  mineral  matter 
than  incisors  (Bibra).  The  relation  of  the  calcium 
phosphate  to  the  calcium  combined  with  carbonic  acid, 
and  in  some  analyses  with  chlorine  and  fluorine, 
suggests  an  analogy  between  the  composition  of  the 
enamel  and  the  mineral  apatite. 


CHEMISTRY    OF    THE    EYE 

The  sclerotic  coat  dissolves  almost  completely  in 
boiling  water,  and  the  liquid  obtained  is  a  solution  of 
gelatin  and  chondrin. 

The  cornea  furnishes  chondrin  with  boiling  water  ; 
it  also  contains  myosin  and  an  alkaline  albuminate. 

The  choroid  coat,  on  being  boiled  with  water,  also 
furnishes  gelatin. 

The  following  analysis  of  the  crystalline  humour  was 
made  by  Berzelius  : — 

Water          .  .  .68.0 

Albuminous  matter      ....     35.9 
Aqueous  extract  and  salts    .         .  2.4 

Alcoholic  extract  .          .          .        1.3 

Membrane  .          .          .          .          .          .2.4 

100.0 

The  albuminous  matter  coagulates  in  certain  cases, 
and  cataract  is  then  produced,  on  account  of  the  opacity 
of  the  crystalline  lens. 


406  ANIMAL    CHEMISTRY. 

Lassaigne  analyzed  the  opaque  crystalline  lens  of  the 
eye  of  a  horse,  and  found — 

Coagulated  albuminous  matter     .  .     29.3 

Calcium  phosphate       .         .  .51.4 

„        carbonate        .         .         .  .       l.(i 

Portion  soluble  in  water  17.7 


100.0 

The  iris  is  chiefly  elastin  and  connective  tissue. 
The  retina  is  an  expansion  of  the  optic  nerve,  which 
has  the  composition — 

Water        .         .  .     V'2M 

Albumen    ....  .       6.25 

Fatty  substances         ...  .85 


100.00 

AQUEOUS  HUMOUR  OF  THE    EYE. — Berzelius   found 
in  this  liquid- 
Water  .     98.10 
Lactate,  chloride  of  sodium         .         .       1.15 
Sodium  hydrate ...                  .0.75 


100.00 
It  also  contains  a  small  quantity  of  albumen. 


PUS.  407 


EXUDATIONS. 

THE  name  exudations  is  given  to  liquids  formed  at 
the  expense  of  the  blood,  in  consequence  of  an  inflam- 
mation which  arrests  the  circulation  of  this  fluid. 

Exudations  differ  from  transudations  by  containing 
fibrin,  much  albumen  and  blood  globules,  and  in 
being  more  dense. 


PUS 

Is  a  yellowish-white,  viscous,  neutral  liquid,  or 
alkaline  if  the  pus  is  unhealthy. 

It  is  formed,  like  the  blood,  of  a  liquid  (serum)  in 
which  are  corpuscles.  These  are  about  .01  mm.  in 
diameter ;  they  contain  a  viscous  liquid  and  nuclei 
enclosed  in  a  membrane.  The  colourless  globules  of 
mucus  and  lymph  resemble  these  corpuscles ;  they  are 
designated  in  general  as  cystoid  corpuscles. 

Pus  exposed  to  the  air  usually  becomes  acid,  pro- 
ducing margaric,  butyric,  and  other  homologous  acids. 
Ammonium  sulphide  is  afterwards  formed,  and  the  mass 
undergoes  putrid  fermentation. 


408  ANTMAL    CHEMISTRY. 

Pus  contains  15  to  16  per  cent,  of  soluble  matter,  the 
most  important  of  which  is  albumen.  The  existence  of 
a  substance  called  pyin  has  been  detected  in  it,  but 
according  to  Lehman  this  body  is  an  abnormal  product. 
It  generally  contains  a  larger  proportion  of  soluble  salts 
than  the  serum  of  the  blood. 

Boedecker  found  in  a  pus  slightly  alkaline : — 

Water 88.76 

Albumen    .                  ....  4.38 

Pyin 4.65 

Fatty  bodies  and  cholesterin       .         .  1.09 
Sodium  chloride         .         .         .         .0.59 

Other  alkaline  salts    ....  \32 

Earthy  phosphates     ....  0.21 


100.00 

Certain  varieties  of  pus  have  the  property  of  impart- 
ing a  blue  tinge  to  liiieii.  Fordos  has  discovered  the 
principle  which  produces  this  coloration :  it  is  a 
c/ystalline  substance  which  he  has  named  pyocyanin. 

Pus  swells,  and  assumes  the  appearance  of  gelatin  on 
being  mixed  with  ammonium  hydrate.  This  reaction 
distinguishes  it  from  mucus. 

Pure  pus,  placed  in  a  vessel  and  allowed  to  remain 
for  several  hours,  separates  into  two  layers.  The  lower, 
curdy  layer  contains  the  globules  and  the  solids;  the 
upper,  opalescent  layer  constitutes  the  serum. 


PUS. 


409 


G.  Robin  gives  the  following  analysis  of  the  serum  in 
1,000  parts:  — 


Water       .... 

Sodium  phosphate     . 

Phosphate  of  soda     . 

Earthy  and  ammonio- 
magnesium  phosphates  . 

Sulphates  and  carbonates 
of  sodium  and  potassium 

Salts  of  iron  and  silica 

Salts  with  organic  acids, 
formiates,  butyrates, 
valeriates,  etc. 

Leucin,  tyrosin,  and  ex- 
tractive substances 

Serolin      .... 

Cholesterin 

Fatty  bodies     . 

Lecithin  .... 

Meta- albumen  and  serin  . 


937.86  to  970.55 


3.11 

traces 

0.50 

1.87 
.16 


traces 

15.00 
1.00 
3.50 

10.00 
6.00 

11.00 


Among  the  extractive  substances    there 


4.66 
2.22 

2.20 

3.11 
.96 


1.00 

20.00 
8.30 
10.00 
19.00 
10.00 
48.00 
have  been 


found :  Paraglobulin,  tyrosin,  leucin,  xanthin,  urea, 
glucose  (in  diabetes),  bilirubin,  uric  and  chlorrho- 
dinic  acids  (in  necrosis),  and  a  special  pus  product, 
hydropsin. 


LIST   OF   ORIGINAL   AUTHORITIES. 


1.  Annalen    diT     Chemie    und 

Pharmacie ;    v.  Liebig  u. 
Wohler. 

2.  Annalen     dor     Physik    und 

Chemie  von  Poggendorf. 

3.  Archiv  der  Pliarmacie. 

4.  Bulletin  do  la  societi-  d'en- 

courag. 

5.  Bulletin    de    la    soeiete    de    ;    22 

Mulhouse. 

I 

6.  The  Engineer. 

7.  Cheruisches  Centralblatt. 

8.  Chemical  News. 

9.  Comptes  rendus. 

10.  Deutsche  Industriezeit. 

11.  Zeitschrift  fiir  Biologic. 

12.  Gewerbeblatt,  Sachsisches 

13.  ,,  Breslauer. 

14.  ,,  Hessisches. 

15.  ,,  Wiirtemberger. 

16.  Wieck's  Illustr.  deutsch. 

Gewerbztg. 

17.  Journal  de  Pharmacie  et  de 

Chimie. 


IK. 
19. 

20. 
21. 


23. 
24. 

25, 

26, 

27. 
28, 
29, 


Journal        fur        praktischc 

Chemie. 
Bayr.  Industrie  u.  Gewerbf- 

blatt. 

London  Journal  of  Arts. 
Lehrbuch      der      physiol  •..•;. 

Chemie.     Gorup-Besan>  /. 

Fourth  F.d.  187S. 
Mittheilungen    <les     (je\\vr- 

bevereins  fur  Hannover. 
Reimann's  Farberzeitung. 
Pharmaceut.  Centralhalle  v. 

Eager. 
Photogr.    Archiv.    v.   Liese- 

gang. 

Polytechn.  Centralblatt. 
Mechanics'  Magazine. 
Dingier' s  Polytechn.  Journal, 
Polytechn.  Notizblatt  v. 

Bottger. 

Milehzeitung  (Dantzic). 
Practical  Mechanics' Journal. 
Q.uarterlyJourn.of  the  Chem. 

Soc. 


LIST    OF    ORIGINAL    AUTHORITIES. 


411 


:);{.  Ackermann'sGewerbezeitung 
:>4.  Repertory  of  patent  inven- 
tions. 

35.  Technologist©. 

36.  Jahresbericht  der  Chemie 

37.  Zeitschrift    fiir    analytische 

Chemie. 

38.  Journal  of  Applied  Chemistry. 

39.  Zeitschrift  des  allgem.  oster- 

reich.  Apotheker-Vereins. 

40.  Pliarmaceut.  Zeitschr.  f. 

Russland. 

41.  \Vion.  Acad.  Ber. 

42.  Xcues   Jahrbuch   fiir    Phar- 

macie. 

4:5.  Berg-  und  hiittenmann. 
Zeitung. 

14.  The  Lancet  (London). 

1,3.  Der  Bierbrauer  (Leipsic), 

(6.  Archiv.  Pharm. 

IT.  Gazetta  Chimica  Italiana 

15.  Illsner's  Chem.  -techn.  Mitt- 

heilgn. 

19    Industrieblatterv.  Hager  und 
Jacobsen. 

50.  Photographische  Mittheiluu- 

gen  v.  H.  Vogel. 

51 .  Zeitschrift  des  Vereins  fiir  die 

Riibenzuel^erindustrie 

52.  American  Jour,  of  Pharmacy. 

53.  Photographische    Correspon- 

denz  v.  Hornig. 

54.  Bulletin  beige  de  la  photo- 

gr^phie      par      Deltenre- 
Walker. 

55.  London   Royal   Society  Pro- 

ceedings. 


60. 
61. 


62. 
63. 
64. 
65. 
66. 
67. 
6K. 
69. 
70 
71. 
72. 

73. 
74. 
75. 

76. 

77. 
78. 

79: 
80. 
81, 

82. 
83, 


( Hiemiseh-Technisch  Reperi- 

toriuni. 

Neue  Deut.  Gewb.-Zeitg. 
Wagner's  Jahresbericht  der 

chem.  Technologic. 
Wiirzburg.  gemeinn.  Woch- 

enschr. 
Berichte  der  deutschen  chem . 

Gesellschaft. 

Proceedings    of  the    Frem-h 
Association    for   the    Ad- 
vancement of  Science. 
Lyon  Medicale. 
Scientific  American. 
American  Artizan. 
Journal  fiir  Gasbeleuchtung. 
Mouiteur  Scientifique 
Badische  Gewerbezeitung. 
Der  Naturforscher  (Berlin). 
Deutsche  Weinzeitung. 
Annales  du  Genie  civil. 
Les  Mondes. 
Aunales    de    Chimie    et    de 

Physique. 

Deutsche  Gerberzeitung. 
Chicago  Pharmacist. 
Neues  Repert.  der  Pharm. 
Nature  (London). 
Nacquet's  Modern  Chemistry. 
Schweizer.  Zeitschr.  f.  Phar- 

macie. 

Virchow's  Archiv. 
American  Journal  of  Science. 
Zeitschrift  f.   d.  gesammten 

Naturwissenschaften. 
Zeitschrift  fiir  Chemie. 
Photographic  News. 


412 


LIST    OK    ORIGINAL    AUTHORITIES, 


84.  Brit.  Journ.  of  Photography.         99. 

85.  New  Remedies. 

86.  Philadelphia  Photographer.        100. 

87.  London  Medical  News.  101. 

88.  Moniteur  Industriel. 

89.  Jahresbericht    der    Thier-       102. 

chemie. 

90.  Centralblatt   f.  d.  Papier-       103. 

fabrik. 

91.  Engineering.  104. 

92.  Propagation  Industrielle. 

IK).  Journal  de  1' Agriculture  p.       105. 

Barral  (Paris). 
9-1.  Proceedings   of     the     Am.       106. 

Pharrn.  Ass'ii.     .  107. 

9o.  Re  vista  Pharmaceutioa 

(Buenos  Ayres).  j    108. 

90.  Journal  for  Pharmaci 

(Copenhagen). 
97.  Bulletin  de  la  Societe  Chi-    j    109. 

mique  (Paris).. 
;H    Popular  Science  Monthly.        i    110 


Journ.  of  the  Franklin  In- 
stitute. 

American  Chemist. 
Kunstund  Gewerbe  (Nurem- 
berg). 

Neues  Handwoerterbuoh  der 
Chemie. 

Jacobsen's  Chem.-teoh. 
Repertorium. 

Philosophical  Magazine 
(London). 

Pharm.  Journal  and  Trans- 
actions. 

Pharm.  Zeitnng  (Bunzlau). 

Zeitschriit  fur  Chem.  Gross- 
gewerbo. 

Die  Chem.  Industrie  aui'der 
Austellung  in  Philadc-1- 
phia. 

Zeitschrift  fur  Physioiog. 
Chemie.  TToppe-Seyler. 

Moniteur  de  la  teinture. 


INDEX. 


PAGE. 

Accnapthene,  Ci2Hio=-i54. .  38 
Acetamide,  Ca  Hg  NO=59-  •  J3^ 
Acetanilide,  Cg  Ha  NO— 135.  130 
Acetic  oxide  Gj  He  Os  =102  103 

Acetochlorhydric  glycol 63 

Acetone,  Ca  He  0=58. . .  .99,  108 
Acetyl  acetate,  Q  Ng  Os  . . .  103 
Acetyl  chloride,  Ca  C1H3  O.  103 
Acetyl  hydride  or  aldehyd, 

C2H4Or=44 86 

Acetylamine,  Ca  HS  N=43..  129 
Acetylene,  Ca  Ha  =26. .....  18 

Acetylide,  cuprous 19 

Acid,acetic,  Ca  H4  Os  —60.  .  99 
Acid,  aconitic,  C$  HG  Og  =95  174 
Acid,  acrylic,  Cs  Hi  Oa  —  72.  91 
Acid,  adipic,  CG  HioO.j  =148  91 
Acid,  alloxanic,  Cj  HI  Na  Os  125 
Acid, alpha-cymic,  CjiH^Oa  91 
Acid,  amalic,  CG  H?  Na  0.4  . .  169 
Acid, anchoic,  Cg  HigO4  =riS8  93 
Acid,  angelic,  Cs  HS  Oa  — 108  91 
Acid,  anisic,  Cg  HS  Os  =152.  92 
Acid,  arabic,  CG  HioOs  —342  217 
Acid,  arichidic,  CaoH^Oa  .  .  90 
Acid,  atropic,C9  Hg  Oa  —148  164 
Acid,benzoic,C7  He  Oa  =  126 

91,  109,  126 

Acid,  benzoglycolic  126 

Acid,  butyric,Gi  Hg  Oa  .  ..90,  108 
Acid,  caffetannic 196 


PA6K. 

Acid,  camphic,  CioHieO2o=c9i  168 
Acid,  campholic,  CigHigC^  . .  91 
Acid,  camphoric,CioHi8O4  41,  93 
Acid,  caprylic,  Cg  HjeOa  ...  90 
Acid,  caproic,Ce  HiaOa  =  1 16  90 
Acid,  capric,  QoHaoOa  =172  90 
Acid,  carballylic,  Ce  Hg  Oe  -  95 
Acid,  carbamic,  CHs  NOa  ...  1 1 
Acid,  carbazotic,(Picric) 

CH3N3  07=229 33 

Acid,  carbolic,  C«  He  0=94.  32 
Acid,  carbonic,  C-2  H3  0=62.  92 

Acid,  catechic 196 

Acid,  cerotic,  CavH^O . .  .90,  180 
Acid,  chelidonic,  C?  H4  Og  . .  95 
Acid,  chlorbenzoic,C7  HS  CIO 

=  130-5 l6° 

Acid,  cholalic,  Ca^^Os  =  408  95 
Acid,  cholesteric,  Cg  HioOs  . .  95 
Acid,choloidic,Ca4Hg8O4  =  39O  94 
Acid,  cinnamic,  Cg  Hg  Oa  = 

148 91,  in 

Acid,  citraconic,  Cs  He  ©4  93, 121 
Acid,  citric,  C6  Hg  O7.H2  O  = 

192+18 120,  95 

Acid,  coccinic,  CjsHaeOa  ...  90 
Acid,  comenic,  Ce  H4  Os  .. .  95 
Acid,  coumaric,  Cg  Hg  Os  . .  93 
Acid,  croconic,  Cs  Ha  Os  .  .  95 
Acid,  crotonic,C4  He  Oa  ..91,  178 
Acid,  cumic,  CjoHiaOj  =  164  91 


414 


INDEX. 


PAGE. 

Acid,  cyan  acetic, 

C2  H3  (CN)  O2  =85 103 

Acid,cyanhydric,HCN  =  27.   161 

Acid,  dextroracemic 117 

Acid,  dial  uric,  Cj  H4  N2  Oj  125 
Acid,  dinitrobenzoic, 

C7H4(NO2)2O2  =212...   no 
Acid,  doeglic,  QgHseOa  =  296  91 

Acid,  elaidic 177 

Acid,  erucic,  CziH&Oz  =338.  91 
Acid,  ethalic,  QeHsaOij  =256  179 
Acid,  ethylsulphuric, 

C2H5HSO4  =126 71 

Acid,  formic,  CH2  O2  =50.98,  90 
Acid,  fumaric,C4  H4  O^  =116  93 
Acid,  gallic,  €7  H6  O5  .  .95,  197 
Acid,  glucic,  Ci2  Hg  Og  =306  186 
Acid,  glyceric,  Cs  HR  04  ...  93 
Acid,  glycolic,  C2  H.j  Og  .60,  92 
Acid,  guaiacic,  Ce  Hg  O$  . . .  92 
Acid,  gummic,  Ci2  H22  On..  217 
Acid,  hippuric,  Cg  Hg  NOs  ..  125 
Acid,  insolinic,  Cg  Hg  04  . . .  94 
Acid,  itaconic,  Cs  He  CM  . .  121 
Acid,  lactic,  Cs  HS  O.s  -.92,  122 
Acid,  lauric,  CujHaiOij  =  200  90 
Acid,  leucic,  Ce  Hj2Oa  =  132.  92 
Acid,  lichenstearic,  Cg  HiiOs  92 
Acid,  lithic,  C5  H4  N.,  O3  . .  123 
Acid,  lithofellic,  QoHseO,]  .  .  93 
Acid,  malic,  Q  He  Os  =134  115 
Acid,  malonic,  Cs  H,j  O<  ...  93 

Acid,  mannitic 183 

Acid,  margaric,  CnHsjOa  ...  177 
Acid,  meconic,  C7  II.i  O.  .  .  .  143 
Acid,  melissic,  CsglieoOa  .  .  90 


PAGK. 

Acid,  mellitic,  C4  H2  04 94 

Acid,  mesoxalic,  Cs  H2  Os  . .    94 

Acid,  metagummic 217 

Acid,  monochloracetic, 

C2  Cl  Ha  O2  =94.5 201 

Acid,  moringic,  C^HysOz  .  .  91 

Acid,  morintannic 196 

Acid,  mucic,  CG  HS  Og  =205  95 

Acid,  myristic,  CuHasOao-  •  •  90 

Acid,  cenanthalic,  Cr  Hi4O2  90 

Acid,  cenanthic,  C^HasOs  .  .  92 

Acid,  oleic,  CisHsiOa  =282.  91 

Acid,  opianic. 127 

Acid,  oxalic,  C2  H2  O,t  .  ..93,  112 

Acid,  oxamic,  C2  HS  NOg  .  .  n 

Acid,  oxybenzoic,  Cj  He  Oa  195 

Acid,  oxybutyric,  Cj  HS  Os  92 

AcidjOxycuminic,  CioHjaOs  92 

Acid,oxynapthalic,  CioHe  04  94 

Acid,  oxy  valeric,  Cs  HioOa  . .  92 
Acid,  palmitic,  CigHsjOjj  .90,  177 

Acid,  parabanic,C,3  H2  N2  Os  125 

Acid,  paraflnic,  C-^H^Oz  •  •  23 

Acid,  paralactic 122 

Acid,  paramalic,  Ci  H4  04  . .  116 

Acid,  paratartaric 117 

Acid,  pectic,  CieH^Os  =294.  218 

Acid,  pectosic 218 

Acid,  pelargonic,  Cg  HisOs  ...  90 

Acid,  phenic,  Ce  He  0—94.  .  32 
Acid,  phenylsulphuric, 

Q  H6  04  8  =  174 32 

Acid,  phloretic,  Cg  HioOa  .  .  92 

Acid,  phtalic.Cs  He  04  =150  94 

Acid,  physetoric,  CieHsoO-^  ..  91 

Acid,  picric,  C6  H3  (NO2  )s  O  33 


INDEX. 


415 


Acid,  pimelic.C?  Hj2O4   ....  93 

Acid,  pinaric.CijoHgoOa  —302  41 

Acid,  pinic,  C^H.soOa  =  302 . .  91 

Acid,  piperic,  CijHioOt  =218  94 
Acid,  propionic,  C.s  Hp  O-2  78,  90 

Acid,  prussic,  HCN=27_    . .  161 

Acid,  pyrogallic,  CB  H«  Os  . .  198 

Acid,  pyroligneous 100 

Acid,  pyromeconic,  Cs  H4  Oa  92 
Acid,  pyrotartaric,  Cs  Hg  04 

-i32 93.  "7 

Acid,  pyroterebic,  Ce  HioOa  •  -  91 
Acid,  pyruvic,  Cs  H^  Os  —88  92 
Acid,quinic,  C?  Hj-^Ofi  =144-  93 

Acid,  quinotannic 196 

Acid,racemic,Ci  HR  Og  =150  117 
Acid,  ricinoleic,  CisH^iOs,  92,  180 
Acid,  roccellic,  CnHssOj  .  .  93 
Acid,  salicylic,  Cr  HS  Os  195,32,92 

Acid,  sarcolactic 122 

Acid,  scammonic,  CjsH-^gOa  92 
Acid,  sebic,  QoHigCU  =202..  93 
Acid,  sorbic,  CB  Hg  O-j  =112.  91 
Acid,  stearic,  CisH^Oa  .  .90,  177 
Acid,  suberic,Cg  Hi4O4  =174  93 
Acid,  succinic,  C4  He  04  93,  115 
Acid,  sulphocarbolic, 

C6H6SO.,  =174 33 

Acid,  sulphoglucic 185 

Acid,  sylvic, CaoHsoO-j  =302.  41 
Acid,  tannic,  Cy;H-Z2Oi~  —  6i8  196 
Acid,  tartaric,C<  Hg  Ot;  .  ..116,  95 
Acid,  tartrelic,  Ci  H4  O5  . .  .  117 
Acid,  tartronic,  Cs  H4  Oj  .  .  94 
Acid,  terebic.C;  HioOj  =  158  93 
Acid,  terechrysic,  Ce  He  O±  94 


Acid,  thionuric, 

C4  Hs  NO3  SO3  =  195.  ...  125 
Acid,  thymotic,  QiH^Os  ..  92 
Acid,  toluic,  Cs  Hg  Oj  =136  91 
Acid,  trichloracetic, 

HQ  C13  O2  =  163.5  .......   102 

Acid,  tropic,  Cg  HioOa  =  166.  164 
Acid,  uric,C5  H4  N4  O3  =  168  123 
Acid,  valeric  or  valerianic, 

Ce  HioOg  =  102  ........  109,  90 

Acid,   veratric,  Cg  HjoOs  ...     94 
Acid,  xylic,  Cg  HioC>2  =150.     91 
Acids  .....................     95 

Acids,  aromatic  ............     91 

Acids,  fatty  ................     90 

Acids,  general  methods  of 

preparation,  .............     96 

Acids,  organic  .............     90 

Acids,  defined  .............     95 

Acids,  polyatomic  ..........   112 

Acids,  pyro  ................     97 

Aconitina,  CsoH47NO7  =533.  165 
Albumen  .................   228 

Alcohol,  amylic,  CsHi2O.56,  45 
Alcohol,  benzyl,  C7  H8  O=io8 


Alcohol,  butyl,  C{  HioO  =  64  45 

Alcohol,  ceryl,C27Ho6O  =  396  45 

Alcohol,   cholesteryl  .......  46 

Alcohol,   cinnyl,  Cg  HioO  .  .  46 

Alcohol,  cuneol  ............  46 

Alcohol,  cymol,  CioHuO..  46 

Alcohol,  melissic,  CsoHeaO  ..  180 
Alcohol,  methyl,  CH4  O.  .45,  46 

Alcohol,  myricyl,  CaoHesO..  45 

Alcohol,  octyl,  Cg  H]«O=  130  45 


INDEX. 


MOB, 

Alcohol,  ordinary,  or  ethyl, 

Qj  Hg  0=46 49 

Alcohol,  propyl,  Cg  HS  O. . .  45 

Alcohol,  sexdecyl,  QeHsjO. .  45 

Alcohol,  sextyl,  Cg  HuO 45 

Alcohol,  vinyl,  Ca  Hg  0=46  45 

Alcohol,  xylyl,Cg  HioO=  122  46 

Alcohols,  diatomic 58 

Alcohols,  monatomic 44 

Alcohols,  polyatomic. 59 

Alcohols,  sulphur 82 

Alcohols,  selenium 82 

Alcohols,  tellurium 82 

Alcohols,  tetratomic 59 

Alcohols,  triatomic 64 

Aldehyds 86 

Alizarin,   QtoHg  Oa  =  1 74 . . .  39 

Alkalamides 136 

Alkaloids ...  127 

Allantoin,    €4  H6  N4  Os  =158 

"4 

Alloxan,  C4  H4  Nj  Og  =160.  125 

Alloxantin,  Cg  HioN4  OIQ.  .  123 

Allyl  iodide,  C3  H5  1=  168 . .  57 

Allyl  sulphide,  Cg  HioS=  1 14  57 
Allyl  sulpho-cyanide, 

C4HsNS  =  99 57 

Allylamine,  Cs  H;  N=57. . .  127 

Allylene,  Cs  H4  =40 20 

Amane,  Cs  Hi2=72 23 

Amber 26,  42 

Amides 136 

Amidoxypropyl, 

C3H4(NH2)0=72 75 

Amines 133 

Ammelide j  72 


FAOX. 

Ammonia  aldehydate, 

CaH4ONH3=6i 87 

Ammonia  citrate  of  iron. . .  121 

Ammoniacum 43 

Ammonias,  compounds 131 

Ammonium,  cyanate,CH4  Na  172 

Ammoniums 137 

Ammoniums,  quarternary. .  136 

Amygdalin,  C^H^NOn —  193 

Amyl,  acetate,  C?  H^Os  . .  56 

Amyl,  chloride,  CsHnCl..  56 

Amyl,  hydride,  Cs  Hj2=  72.  23 

Amylamine,  Cs  HisN=87. .  121 

Amylene,  Cs  Hio=7o 23 

Anhydride,  tartaric, 

C4H4  05=132 "7 

Aniline...., 30,127,  131 

Anthracene,  Ci4Hio=i78.  .29,  39 

Arabin  CisHazOn  =  342 217 

Arbutin  CisHjeOt  =284 193 

Aricina  CssHgcNa  Oi  =397. .  129 

Arnicin 42 

Aromatic  compounds 89 

Arsines 128 

Asphalt 26 

Assafoetida 43 

AtropiaCnHssNOs  =289.164,129 

Balsams 41 

Bases  organic, 125 

Bases  quarternary, 136 

Bassorin 218 

Belladona 164 

Benzene  Cg  He  =  78 27 

Benzine 24 

Benzoic  aldehyd,  C7  H6  O..  86 

Benzol,  Ce  H6  =78 27 


INDEX. 


417 


PAGE. 

Benzone 119 

Benzonilrile no 

Benzyl  chloride 126 

Benzylene 20 

Bezoar 267 

Bidecane 28 

Bidecyl  hydride 23 

Bilifulvin 257 

Bilirubin 257 

Biliverdin 257 

Bile 250 

Bile,  action  on  food 258 

Bitumen 26 

Biuret 172 

Blood 272 

Blood,  action  of  different 

gases  on  the 291 

Blood,  chemical  pathology 

of  the 294 

Blood,  coagulation  of 276 

Blood,  gases  of  the 288 

Blood  globules 281 

Blood,  iron  of  the 287 

Blood,  uses  of 293 

Bones 399 

Borneol 58 

Brain  constituents 394 

Brandy 52 

Brucia 161,  129 

Butane 23 

Butter 179 

Butyl  hydride 23 

Butylamine 128 

Butylene 20,  22 

Cacodyl 79,  105 

Caffeia  (caffein) 130,  168 


PAGE. 

Campholic  alcohol 117 

Camphor,  artificial 37 

Camphor 40 

Camphor,  monochlor 41 

Camphor,  oxy- 41 

Camphor  of  Borneo 58 

Cantharidin 168 

Candles 176 

'Cannabin 42 

Caoutchouc 36,  43 

Caprylamine 127 

Caramel 190 

Caramelane 190 

Caramelene 190 

Caramelin  ....    190 

Carbo-hydrates,  defined 7 

Carbon  dioxide 313 

Caries 401 

Carbonic  ether 74 

Cartilagein 392 

Casein,  animal 226,  233 

Casein,  vegetable 219,  234 

Castor  oil 180 

Castorin 42 

Cellulose  (cellulin) 202 

Cerasin 217 

Cerebrin 39^ 

Cetene 23 

Chitin 184 

Chloral 87 

Chloral  hydrate 88 

Chloroform 47 

Chloropropyl 1 15 

Cholera 2*96 

Cholesterilene 255 

Cholesterin 255 


418 


INDEX. 


PAGE. 

Cholesterophan 169 

Cholin 251 

Chondrin .327,  214,  392 

Chondroglucose 392 

Chyle 269 

Chyme 268 

Chymosine 247 

Cinchonia    (cinchonine).  129,  156 

Cinchonicia  (cinchonicine).  .  158 
Cinchonidia     (cinchonidine) 

158,  129 

Cinnamene 38 

Coagulum 281 

Codeia 146,  129 

Colchinia 163 

Colloidin 375 

Collodion 208 

Colophony 41 

Compound  ammonias 131 

Conia  (conine) 141,  129 

Conicin 1 29 

Conifer  in 193 

Convolvulin 193 

Conylia 141,  129 

Cotarnin 147 

Cream  of  Tartar 1 16 

Creatin iSS,  386 

Creatinin 386 

Creosote 34 

Cresofol 29,  34 

Crotonylene 20 

Cumene 28 

Cumidin 127 

Cuprous  acetylide 20 

Curari 163 

Curarina 


-I 


PAGE. 

Cyanopropyl 15 

Cyclamin 193 

Cymene 38 

Cymogene 24 

Cymol 41 

Cystin 353 

Paphnin 193 

Daturia,  (atropia) 164,  129, 

Decane 24 

Dextrin 212,  214 

Dental  tissue 403 

Diabetes   327,  347 

Diastase 212 

Diethylamine 128 

Diethylpropyl 15 

Diethylenic  diamine 170 

Digestion 237 

Digitalin 166 

Digitin 166 

Dimethylphosphine 128 

Draconyl   38 

Dropsy 297 

Dulcite,  (dulcose) 183,   181 

Duodecylcne 23 

Dysentery   266 

Dystisin 253 

Elaidin   175 

Elaine 175 

Elastin 389 

Elemi 43 

Emetia 167 

Emetics 119 

Emydin 226 

Ergotin 42 

Erythrite 49 

sculin 193 


I  N  D  E  X  . 


419 


PAOK. 

Essence  of  mirbane 29 

Essence  of  thyme 34 

Essential  oil  of  cloves 37 

Essl.  oil  of  bergamot 37 

Essl.  oil  of  copaiba 37 

Essl.  oil  of  cubebs 37 

Essl.  oil  of  elemi 37 

Essl.  oil  of  juniper 37 

Essl.  oil  of  lemon 37 

Essl.  oil  of  orange 37 

Essl.  oil  of  pepper 37 

Ethal 179 

Ethane 13,  15,  23 

Ethene 13,   15 

Ether,  acetic 73 

Ether,  butyric 81 

Ether,  chlorhydric 75 

Ether,  common   70 

Ether,  cyanhydric 77 

Ether,  ethyl 70 

Ether,  formic Si 

Ether,  hydriodic 76 

Ether,  hydrosulphuric 83 

Ether,  oenanthvlic 81 

Ether,  oxalic 74 

Ether,  oxamic 117 

Ether,  sulphuric 70 

Ether,  valerianic Si 

Ether,  vinic 70 

Ethers 69 

Ethers,  simple 69 

Ethers,  compound 73 

Ethers,  miscellaneous 81 

Ethers,  mixed 38 

Ethine 13 

Ethyl .• 15 


Ethvl  chloride  

75 

Ethyl  cyanide  

77 

Ethyl  formiatc.  

9 

Ethylglvcol  

6  1 

Ethyl-hexyl  ether   

84 

Ethyl  hydride.    . 

-=3 

Ethyl  iodide  

76 

Ethyl  mercaptan  

83 

Ethylmethylaniline  

30 

Ethyl  oxide  

69 

Ethyl  sulphide  

83 

Ethylamine  132 

127 

Ethylene.  .  .  '.  

21 

Ethylene  bromide  

6  1 

Ethylene  chloride  

76 

Ethylene  oxide  

62 

Eucalin  

183 

Eye,  chemistry  of  the   

4°5 

Excrements  

265 

Excretin  

265 

Extosis  

401 

Exudations  

407 

Fats  

174 

Fatty  acid  series  

90 

Ferment,  bile  

258 

Fermentation,  acetic  

IOO 

Fermentation,  alcoholic.  .  .49, 

181 

Fermentation,  gallic  

197 

Fermentation,  lactic  

122 

Ferrocvanide  of  potassium  . 

I72 

Fibrin  226, 

-'3' 

Flesh  

382 

Flour  

215 

Food,  respiratory  

223 

Food,  plastic  

224 

Food,  transformation  of.  .  .  . 

321 

420 


I  N  D  E  X. 


Formene 23 

Frankincense 43 

Fulminates 54 

Fusel  or  tbusel  oil 56 

Galactose 187,  182 

Gas,  illuminating ji 

Gasolene 24 

Gastric  juice 242 

Gasterase  pepsin 247 

Gelatin ^34' 399 

Glucosane 185 

Glucose 1 80,  182,  184,  343 

Glucose  in  the  liver 323 

Glucosides 192,  184 

Glue 235 

Gluten 216 

Glycerin 64 

Glycocol,  zincic 126 

Glycogen 214,  250,324 

Glycol,  amyl. ...  59 

Glycol,  butyl 59 

Glycol,  diethyl 61 

Glycol,  ethyl 61 

Glycol,  hexyl 59 

Glycol,  monochlorhydric.  .  .     62 

Glycol,  octyl 59 

Glycol,  ordinary 59 

Glycol,  propyl 123 

Grape  sugar 182 

Guano   124 

Gum 216 

Gum  arabic 217 

Gum  resins 41 

Gun-cotton 207 

Haematin 286 

H<ematocrystallin 225 


PAGE." 

Haemoglobin 284,  226 

Helicin 194 

Heptyl  hydride 23 

Heptane 23,   24 

Heptylene 22 

Hexadecane 24 

Hexadecyl  hydride 24 

Hexane 23 

Hexylene 22 

Hexyl  hydride 23 

Hoffmann's  anodyne 73 

Homologous  series  12 

Honey 192 

Hydrides 23 

Hydrocarbons 18 

Hydrocarbides 18 

Hydrocarbides,    extra-terres- 
trial       40 

Hydrocephalus  fluid  374 

Hydrogen  carbides 18 

Hydropical  fluid 375 

Hydrosulphuric  Ether 83 

Hyosciamine 164 

Ictithin 226 

Indicun 342 

Indigogen 343 

Indiglucin   343 

Indigo 130 

Inosite  (inosin) 182 

Intestinal  concretions 267 

Intestinal  fluids 264 

Intestinal  gases 265 

Inulin 214 

lodomorphia 145 

Iron  of  the  blood 287 

Isatin 38 


INDEX. 


421 


PAGE. 

Isologous  series 12 

Isomerism  . . : 8 

Jalapin 193 

Jervia 163 

Kerosene 24 

Ketones 40 

Lactide 123 

Lactose  or  lactin 191,  182 

Leather 197 

Legamin 219 

Leucocythaemia  . 296 

Levulosan  190 

Levulose 187,  182 

Lichenin 214 

Lymph 270 

Madder 39 

Maltose 182 

Mannitane 183 

Mannite 181,  183 

Marsh-gas 23 

Meconin   143,  147 

Melampyrite 181 

Melanin  389 

Melezitose 182 

Melitose 182 

Mercaptans 82 

Metalbumen 225 

Metamerism  9 

Metaterebenthene 38 

Metastyrol 38 

Methane 13,  15,  23 

Methenyl 15 

Methyl 15 

Methyl  acetate 9 

Methyl  chloride 47 

Methyl  cyanate 131 


PAGE. 

Methyl  hydride 23 

Methylamine 131 

Methylethylamine 128 

Methylphosphine 128 

Methylpropyl 15 

Milk 376 

Molasses 189 

Monamines 133 

Monochlorcamphor 41 

Monochlorhydrin    66 

Morphia  (Morphine). ...  143,  129 

Mucin 227 

Mucus 372 

Murexide 125 

Muscular  power 316 

Muscular  tissue 283 

Musculin 232 

Myosin 232 

Mycose 182 

Naphtha 24 

Naphthalamine   128 

Naphthalin 27,  38 

Narceia 148,  129 

Narcotina    129 

Neocytes   337 

Neurin 257 

Nevrilemma 393 

Nicotina 139,  129 

Nicotyl 140 

Nicotylia 139,  129 

Nitrilebases 124 

Nitrobenzol 29 

Nitrogenous  substances.  . . .  223 

Nitroglycerine 66 

Nitryls,  or  cyanhydric  ethers  134 

Nonane 23 


422 


INDEX. 


PAGE. 

Nonyl    hydride 23 

Nonylene 22 

Nutrition 316 

Nutrition,    role   of    mineral 

compounds   in 330 

Octane 23 

Octylglycol 59 

Octyl   hydride 23 

Octylene 22 

Oils,  fatty 174 

Oils,   essential 36 

Olein 175 

"  Oleomargarine" 179 

Oleo-resins 42 

Opium 142 

Orcin 193 

Organizable  substances 205 

Organometallic  compounds.     78 

Ossein 226,  234 

Osseous  tissues 399 

Oxamide 74 

Oxanthracene 39 

Oxycamphor 41 

Oxygen 311 

Pancreatic  juice 261 

Pancreatin 262 

Para-arabin 192 

Paralbumen 226 

Plants,  respiration  of 201 

Plants,  nutrition  of 204 

Poly  amines 170 

Polymerides 9 

Polymerism 9 

Populin 193 

Pancreatin j  6  .> 

Pancreatic  juice 261 


PACK. 

Paraffin 22,     24 

Papaverin 129,  148 

Paramorphia 148 

Paramylene 22 

Parapeptone 249 

Pectin 218 

Pectose 218 

Pentadecane 24 

Pentadecyl   hydride 24 

Pepsin 227,  247 

Peptones 225,  249 

Petroleum 24 

Phenol  32 

Phenol,  potassic 32 

Phenol,   trinitric 30 

Phenyl  30 

Phenyl  hydrate 32 

Phenylamine 127 

Phlorizin  193 

Phlorylol 34 

Phosphines 128 

Phtalidamine 127 

Picrotoxin  160 

Finite 181 

Piperidine 141 

Piperine 141 

Pitch,  Burgundy 42 

Plethora 295 

Potassium,  formiate 88 

Propane 13,  15,  23 

Propenyi 15 

Propine 13 

Propone 13 

Propyl 15 

Propy  1    hydride 23 

Propylamirie 127 


INDEX. 


423 


PAGE. 

Propylene 22 

Proplene  iodide 64 

Protein 225 

Ptyalin 212,  227,  238 

Pus 407 

Pyin 227,  407 

Pyocyanin 408 

Pyrethrin 42 

P}-rocatechin 352 

Pyrolignite 106 

Pyroxylin 207 

Quercite 181 

Quercitrin ...    193 

Quinia,  (quinine) 151,   129 

Quinicia 154,   129 

Quinidia 129 

Quinidia,  oxalate  of 155 

Quinoidin 158 

Quinolein,    (quinolin)  130,153,157 

Quinovin 193 

Rachitis     402 

Radicles,  denned 14 

Radicles,    organometallic.  . .      78 
Radicles,  organometalloid .  .     Si 

Reagent,  Fehling's 187 

Reagent,   Haines' 187 

Reagent,  Trommer's 186 

Resins 25,  41 

Respiration 272,   301 

Retinasphalt 25 

Retinite 25 

Rhigolene 24 

Rice 216 

Rochelle  salt 118 

Rosanilin 31 

Rutylene 20 


PAGE. 

Rye . ., 216 

Saccharide 186 

Saccharoses 182 

Salicin 194 

Saligenin 194 

Salivaj 237 

Saponification 176 

Saponin 193 

Scurvy 297 

Semen  . 371 

Serosity 374 

Serum 278 

Sinapolin 58 

Sinnamin 58 

Soaps 176 

Sodium  ethyl So 

Sodium  sulphocarbolate.  ...     33 

Solanidia   (solanidine) 165 

Solania  (Solanine),.  .  .  165,129,193 

Sorbin 182 

Spermaceti 179 

Spirit  of  Mindererus 105 

Stannethyl 79 

'Stannethyl  iodide 79 

Starch 210 

Stearin    (stearine). . .    174 

Stearine  candles 176 

Stercorin 257,  265 

Stibines    128 

Stibyl    119 

Strychnia  (strychnine).  .159,   129 

Styrol 38 

Sucrates 190 

Sugars 181 

Sugar  of  milk 191,  182 

Sweat 370 


424 


INDEX. 


PAGE. 

Synovia , 374 

Syntonin 229,  232 

Tannin 196,  193 

Tartar  emetic 1 16 

Taurin 254 

Teeth 403 

Tetrachloropropyl 15 

Tetradecane 24 

Tetradecyl   hydride 24 

Tetradecylene 22 

Tetrethylammonium 133 

Thebaia 148,  120 

Theia  (theine) 168,  130 

Theobromin 169,  130 

Thymol 34 

Thiosinnamin 58 

Tissues 388 

Tissues,  areolar 388 

Tissues,  recticular 387 

Tissues,  cartilagenous 391 

Tissues,  nerve.    393 

Tobacco 140 

Toluene 28 

Toluidin 127,  130 

Transpirations 370 

Trehalose 182 

Trichlorhydrin 66 

Trichloroxypropyl 15 

Tridecane 27 

Triedecyl  hydride ,     24 


PAGE. 

Tridecylene 22 

Triethylamine 135 

Triethylarsine 128 

Triethylenic,  diamine 170 

Triethylstibine 128 

Trimethlamine 128 

Trimethylphosphine 128 

Tunicin 184,  209 

Turpentine 35 

Tvpes,  organic 10 

Typhoid  fever 266,  296 

Urinary  calculi 353,  368 

Urinary  deposits 352,  364 

Urine 333 

Urine,  analysis  of 356 

Urochrome 343 

Uroglaucin 343 

Urorubroh?ematin 352 

Urrhodin .  .    343 

Uroxanthin 343 

Wax 1 79 

Whiskey 52 

Wines 32 

Wood  spirit 49 

Xylene 28 

Xylidin 127 

Xylyl  alcohol 46 

Zinc,  ethyl 79 

Zinc,  glycol 79,  126 


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